At this time, no definite cause of anorexia nervosa has been determined. However, research within the medical and psychological fields continues to explore possible causes.
Some experts feel that demands from society and families could possibly be underlying causes for anorexia. For many individuals with anorexia, the destructive cycle begins with the pressure to be thin and attractive. A poor self-image compounds the problem.
Other researchers feel that this disorder can stem from a particular dysfunction often seen in families of anorexia patients. In one particular type of dysfunction, family members become so interdependent that each cannot achieve their identity as an individual.
Thus, family members are unable to function as healthy individuals and are dependent on other family members for their identity. In children, part of this dysfunction includes a fear of growing up (especially girls).
Restrictive dieting may prevent their bodies from developing in a normal manner, and in their thinking, restricts the maturational process and maintains the parent-child relationship that the family has come to rely on.
Approximately 95% of those affected by anorexia are female, but males can develop the disorder as well. While anorexia typically begins to manifest itself during early adolescence, it is also seen in young children and adults.
In the U.S. and other countries with high economic status, it is estimated that about one out of every 100 adolescent girls has the disorder. Caucasians are more often affected than people of other racial backgrounds, and anorexia is more common in middle and upper socioeconomic groups.
According to the U.S. National Institute of Mental Health (NIMH), an estimated 0.5% to 3.7% of women will suffer from this disorder at some point in their lives.
Many experts consider people for whom thinness is especially desirable, or a professional requirement (such as athletes, models, dancers, and actors), to be at risk for eating disorders such as anorexia nervosa.
Anorexia nervosa, commonly referred to simply as anorexia, is one type of eating disorder. More importantly, it is also a psychological disorder. Anorexia is a condition that goes beyond out-of-control dieting.
A person with anorexia initially begins dieting to lose weight. Over time, the weight loss becomes a sign of mastery and control. The drive to become thinner is actually secondary to concerns about control and/or fears relating to one's body.
The individual continues the endless cycle of restrictive eating often to a point close to starvation in order to feel a sense of control over the body.
This cycle becomes an obsession and is similar to any type of drug or substance addiction.
Panic attacks may be symptoms of an anxiety disorder. These attacks are a serious health problem in the U.S. At least 1.7% of adult Americans, or about 3 million people, will have panic attacks at some time in their lives, with the peak age at which people have their first panic attack (onset) being 15 to 19 years.
Another fact about panic is that this symptom is strikingly different from other types of anxiety; panic attacks are so very sudden and often unexpected, appear to be unprovoked, and are often disabling.
Once someone has had a panic attack, for example, while driving, shopping in a crowded store, or riding in an elevator, he or she may develop irrational fears, called phobias, about these situations and begin to avoid them.
Eventually, the pattern of avoidance and level of anxiety about another attack may reach the point where the mere idea of doing things that preceded the first panic attack triggers future panic attacks, resulting in the individual with panic disorder being unable to drive or even step out of the house.
A panic attack typically lasts for several minutes, is one of the most distressing conditions that a person can experience, and its symptoms can closely mimic those of a heart attack.
Typically, most people who have one attack will have others, and when someone has repeated attacks with no other apparent physical or emotional cause, or feels severe anxiety about having another attack, he or she is said to have panic disorder.
A number of other emotional problems can have panic attacks as a symptom. Some of these illnesses include post traumatic stress disorder (PTSD), schizophrenia, and intoxication or withdrawal from certain drugs of abuse .
Anxiety attacks that take place while sleeping, also called nocturnal panic attacks, occur less often than do panic attacks during the daytime, but affect about 40%-70% of those who suffer from daytime panic attacks.
During relaxation of the heart (diastole) the left ventricle of the heart fills with blood returning from the lungs. The left ventricle then contracts and pumps blood into the arteries (systole).
The blood pressure during contraction of the ventricle (systolic pressure) when blood is being actively ejected into the arteries is higher than during relaxation of the ventricle (diastolic pressure).
The pulse that we can feel when we place our fingers over an artery is caused by the contraction of the left ventricle.
Blood pressure is determined by two factors: 1) The amount of blood pumped by the left ventricle of the heart into the arteries, and 2) the resistance to the flow of blood caused by the walls of the arterioles (smaller arteries).
Generally, blood pressure tends to be higher if more blood is pumped into the arteries or if the arterioles are narrow and stiff. (Narrow and stiff arterioles, by resisting the flow of blood, increase blood pressure.) This often happens when older patients develop atherosclerosis.
Blood pressure is the force exerted by circulating blood on the walls of blood vessels, and constitutes one of the principal vital signs of life, which also include heart beat, rate of breathing, and temperature. Blood pressure is generated by the heart pumping blood into the arteries and is regulated by the response by the arteries to the flow of blood.
An individual's blood pressure is expressed as systolic/diastolic blood pressure, for example, 120/80.The systolic blood pressure (the top number) represents the pressure in the arteries as the muscle of the heart contracts and pumps blood into them.
The diastolic blood pressure (the bottom number) represents the pressure in the arteries as the muscle of the heart relaxes after it contracts. Blood pressure always is higher when the heart is pumping (squeezing) than when it is relaxing.
Systolic blood pressure for most healthy adults falls between 90 and 120 millimeters of mercury (mm Hg). Normal diastolic blood pressure falls between 60 and 80 mm Hg. Current guidelines define normal blood pressure as lower than 120/80. Blood pressures over 130/80 are considered high.
A heart attack (also known as a myocardial infarction) is the death of heart muscle from the sudden blockage of a coronary artery by a blood clot. Coronary arteries are blood vessels that supply the heart muscle with blood and oxygen.
Blockage of a coronary artery deprives the heart muscle of blood and oxygen, causing injury to the heart muscle. Injury to the heart muscle causes chest pain and chest pressure sensation.
If blood flow is not restored to the heart muscle within 20 to 40 minutes, irreversible death of the heart muscle will begin to occur.
Muscle continues to die for six to eight hours at which time the heart attack usually is "complete." The dead heart muscle is eventually replaced by scar tissue.
Approximately one million Americans suffer a heart attack each year. Four hundred thousand of them die as a result of their heart attack.
The blood pressure usually is measured with a small, portable instrument called a blood pressure cuff (sphygmomanometer). (Sphygmo is Greek for pulse, and a manometer measures pressure.) The blood pressure cuff consists of an air pump, a pressure gauge, and a rubber cuff. The instrument measures the blood pressure in units called millimeters of mercury (mm Hg).
The cuff is placed around the upper arm and inflated with an air pump to a pressure that blocks the flow of blood in the main artery (brachial artery) that travels through the arm.
The arm is then extended at the side of the body at the level of the heart, and the pressure of the cuff on the arm and artery is gradually released. As the pressure in the cuff decreases, a health practitioner listens with a stethoscope over the artery at the front of the elbow.
The pressure at which the practitioner first hears a pulsation from the artery is the systolic pressure (the top number). As the cuff pressure decreases further, the pressure at which the pulsation finally stops is the diastolic pressure (the bottom number).
High blood pressure (HBP) or hypertension means high pressure (tension) in the arteries. Arteries are vessels that carry blood from the pumping heart to all the tissues and organs of the body. High blood pressure does not mean excessive emotional tension, although emotional tension and stress can temporarily increase blood pressure.
Normal blood pressure is below 120/80; blood pressure between 120/80 and 139/89 is called "pre-hypertension", and a blood pressure of 140/90 or above is considered high.
The top number, the systolic blood pressure, corresponds to the pressure in the arteries as the heart contracts and pumps blood forward into the arteries.
The bottom number, the diastolic pressure, represents the pressure in the arteries as the heart relaxes after the contraction. The diastolic pressure reflects the lowest pressure to which the arteries are exposed.
Over time, diabetes can lead to blindness, kidney failure, and nerve damage. These types of damage are the result of damage to small vessels, referred to as microvascular disease.
Diabetes is also an important factor in accelerating the hardening and narrowing of the arteries (atherosclerosis), leading to strokes, coronary heart disease, and other large blood vessel diseases. This is referred to as macrovascular disease.
Diabetes affects approximately 17 million people (about 8% of the population) in the United States. In addition, an estimated additional 12 million people in the United States have diabetes and don't even know it.
From an economic perspective, the total annual cost of diabetes in 1997 was estimated to be 98 billion dollars in the United States. The per capita cost resulting from diabetes in 1997 amounted to $10,071.00; while healthcare costs for people without diabetes incurred a per capita cost of $2,699.00.
During this same year, 13.9 million days of hospital stay were attributed to diabetes, while 30.3 million physician office visits were diabetes related. Remember, these numbers reflect only the population in the United States. Globally, the statistics are staggering.
A transient ischemic attack (TIA) is a short-lived episode (less than 24 hours) of temporary impairment to the brain that is caused by a loss of blood supply. A TIA causes a loss of function in the area of the body that is controlled by the portion of the brain affected.
The loss of blood supply to the brain is most often caused by a clot that spontaneously forms in a blood vessel within the brain (thrombosis). However, it can also result from a clot that forms elsewhere in the body, dislodges from that location, and travels to lodge in an artery of the brain (emboli).
A spasm and, rarely, a bleed are other causes of a TIA. Many people refer to a TIA as a "mini-stroke."
Some TIAs develop slowly, while others develop rapidly. By definition, all TIAs resolve within 24 hours. Strokes take longer to resolve than TIAs, and with strokes, complete function may never return and reflect a more permanent and serious problem.
Although most TIAs often last only a few minutes, all TIAs should be evaluated with the same urgency as a stroke in an effort to prevent recurrences and/or strokes. TIAs can occur once, multiple times, or precede a permanent stroke.
A transient ischemic attack should be considered an emergency because there is no guarantee that the situation will resolve and function will return.
A stroke, or cerebrovascular accident (CVA), occurs when blood supply to part of the brain is disrupted, causing brain cells to die.
When blood flow to the brain is impaired, oxygen and glucose cannot be delivered to the brain. Blood flow can be compromised by a variety of mechanisms.
The risk actually varies depending on where you live. This is in part due to the environment you live in, and in part due to the genetic makeup of your family. In the United States, the lifetime risk of developing diabetes is estimated at 33% for males and 39% for females for people born in the year 2000.
It has also been calculated that for those diagnosed before the age of 40, the average life expectancy is reduced by 12 years for men, and 19 years for women.
The risk for developing diabetes increases in certain cases such as the following.
* Genetics - People with a close relative with type 2 diabetes are at higher risk.
* Ethnic background - For example, the actual prevalence of diabetes in the Caucasian population of the US is about 7.2% while in the African American population, it increases to about 11%. In a well known group of Native Americans, the Pima Indians, the prevalence increases to almost 35%.
* Birth weight - There is a relationship between birth weight and developing diabetes, and it's the opposite of what you'd intuitively think. The lower the birth weight the higher the risk of type 2 diabetes.
* Metabolic syndrome - People who have the metabolic syndrome are at especially high risk for developing diabetes.
* Obesity - Obesity is probably the most impressive risk factor. This is in part due to the fact that obesity increases the body's resistance to insulin. Studies have shown that reversal of obesity through weight reduction improves insulin sensitivity and regulation of blood sugar. However, the distribution of fat is important. The classic "pear" shape person (smaller waist than hips) has a lower risk of developing diabetes than the "apple" shape person (larger around the waist). The exact reason for this difference is unknown, but it is thought to have something to do with the metabolic activity of the fat tissue in different areas of the body.
While diabetes is characterized by high blood sugar values, type 2 diabetes is also associated with a condition known as insulin resistance. While there is an element of impaired insulin secretion from the beta cells of the pancreas especially when toxic levels of glucose occur (when blood sugars are constantly very high), the major defect is the body's inability to respond properly to insulin.
Eventually, the pancreas is working it's best to produce more and more insulin, but the body tissues (for example, muscle and fat cells) do not respond and become insensitive to the insulin.
At this point, overt diabetes occurs as the body is no longer able to effectively use its insulin to maintain normal blood sugar levels. Over time, these high levels of sugar result in the complications we see all too often in patients with diabetes.
A key to the understanding of the negative aspects of stress is the concept of milieu interieur (the internal environment of the body), which was first advanced by the great French physiologist Claude Bernard.
In this concept, he described the principles of dynamic equilibrium. In dynamic equilibrium, constancy, a steady state (situation) in the internal bodily environment, is essential to survival.
Therefore, external changes in the environment or external forces that change the internal balance must be reacted to and compensated for if the organism is to survive. Examples of such external forces include temperature, oxygen concentration in the air, the expenditure of energy, and the presence of predators.
In addition, diseases were also stressors that threatened the constancy of the milieu interieur.
The great neurologist Walter Cannon coined the term homeostasis to further define the dynamic equilibrium that Bernard had described. He also was the first to recognize that stressors could be emotional as well as physical. Through his experiments, he demonstrated the "fight or flight" response that man and other animals share when threatened.
Further, Cannon traced these reactions to the release of powerful neurotransmitters from a part of the adrenal gland, the medulla.
Stress is simply a fact of nature—forces from the outside world affecting the individual. The individual responds to stress in ways that affect the individual as well as their environment.
Hence, all living creatures are in a constant interchange with their surroundings (the ecosystem), both physically and behaviorally. This interplay of forces, or energy, is of course present in the relationships between all matter in the universe, whether it is living (animate) or not living (inanimate).
However, there are critical differences in how different living creatures relate to their environment. These differences have far-reaching consequences for survival. Because of the overabundance of stress in our modern lives, we usually think of stress as a negative experience, but from a biological point of view, stress can be a neutral, negative, or positive experience.
In general, stress is related to both external and internal factors. External factors include the physical environment, including your job, your relationships with others, your home, and all the situations, challenges, difficulties, and expectations you're confronted with on a daily basis.
Depressive disorders come in different forms, just as do other illnesses, such as heart disease and diabetes.
Three of the most common types of depressive disorders are discussed below. However, remember that within each of these types, there are variations in the number, timing, severity, and persistence of symptoms.
Depressive disorders have been with mankind since the beginning of recorded history. In the Bible, King David, as well as Job, suffered from this affliction. Hippocrates referred to depression as melancholia, which literally means black bile.
Black bile, along with blood, phlegm, and yellow bile were the four humors (fluids) that described the basic medical physiology theory of that time.
Depression, also referred to as clinical depression, has been portrayed in literature and the arts for hundreds of years, but what do we mean today when we refer to a depressive disorder?
In the 19th century, depression was seen as an inherited weakness of temperament. In the first half of the 20th century, Freud linked the development of depression to guilt and conflict.
John Cheever, the author and a modern sufferer of depressive disorder, wrote of conflict and experiences with his parents as influencing his development of depression.
The tonsils are red, oval clumps of tissue located at the back and to the sides of the throat. This location allows the tonsils to intercept germs as they enter the body through the nose and throat.
They contain infection-fighting cells and antibodies (infection-fighting proteins in the body) that stop the spread of the germs further into the body.
When the tonsils become red, sore, and swollen, this inflammation is called tonsillitis. This is not a specific term, as there are many causes of inflammation of the tonsils. Tonsillitis is a common cause of sore throat.
Sore throat may have many causes. The most common causes of sore throat are infections of the throat and the surrounding structures.
Any inflammation or infection of the pharynx, tonsils, esophagus (the food pipe), or larynx (the top opening part of the windpipe) may cause sore throat.
While many people use the terms sore throat, tonsillitis, and strep throat interchangeably, there are significant clinical differences between these conditions. Understanding the differences can give patients a better idea of how and when to be concerned and when to seek advice from a physician.
Strep throat is only one of many possible causes of throat infection and sore throat. While strep throat is most common in children and adolescents, it can affect people of all ages.
While many people use the terms sore throat, tonsillitis, and strep throat interchangeably, there are significant clinical differences between these conditions. Understanding the differences can give patients a better idea of how and when to be concerned and when to seek advice from a physician.
Strep throat is only one of many possible causes of throat infection and sore throat. While strep throat is most common in children and adolescents, it can affect people of all ages.
The precise reason for the abnormal autoimmunity that causes lupus is not known. Inherited genes, viruses, ultraviolet light, and certain medications may all play some role.
Genetic factors increase the tendency of developing autoimmune diseases, and autoimmune diseases such as lupus, rheumatoid arthritis, and autoimmune thyroid disorders are more common among relatives of patients with lupus than the general population.
Some scientists believe that the immune system in lupus is more easily stimulated by external factors like viruses or ultraviolet light. Sometimes, symptoms of lupus can be precipitated or aggravated by only a brief period of sun exposure.
It also is known that some women with SLE can experience worsening of their symptoms prior to their menstrual periods. This phenomenon, together with the female predominance of SLE, suggest that female hormones play an important role in the expression of SLE. This hormonal relationship is an active area of ongoing study by scientists.
Lupus is an autoimmune disease characterized by acute and chronic inflammation of various tissues of the body. Autoimmune diseases are illnesses that occur when the body's tissues are attacked by its own immune system.
The immune system is a complex system within the body that is designed to fight infectious agents, such as bacteria and other foreign microbes.
One of the ways that the immune system fights infections is by producing antibodies that bind to the microbes. Patients with lupus produce abnormal antibodies in their blood that target tissues within their own body rather than foreign infectious agents.
Because the antibodies and accompanying cells of inflammation can affect tissues anywhere in the body, lupus has the potential to affect a variety of areas.
Sometimes lupus can cause disease of the skin, heart, lungs, kidneys, joints, and/or nervous system. When only the skin is involved, the condition is called lupus dermatitis or cutaneous lupus erythematosus.
A form of lupus dermatitis that can be isolated to the skin, without internal disease, is called discoid lupus. When internal organs are involved, the condition is referred to as systemic lupus erythematosus (SLE).
Leukemia is cancer that starts in the tissue that forms blood. To understand cancer, it helps to know how normal blood cells form.
Normal Blood Cells
Most blood cells develop from cells in the bone marrow called stem cells. Bone marrow is the soft material in the center of most bones.
Stem cells mature into different kinds of blood cells.
A person can become infected with tuberculosis bacteria when he or she inhales minute particles of infected sputum from the air. The bacteria get into the air when someone who has a tuberculosis lung infection coughs, sneezes, shouts, or spits (which is common in some cultures).
People who are nearby can then possibly breathe the bacteria into their lungs. You don't get TB by just touching the clothes or shaking the hands of someone who is infected. Tuberculosis is spread (transmitted) primarily from person to person by breathing infected air during close contact.
There is a form of atypical tuberculosis, however, that is transmitted by drinking unpasteurized milk. Related bacteria, called Mycobacterium bovis, cause this form of TB. Previously, this type of bacteria was a major cause of TB in children, but it rarely causes TB now since most milk is pasteurized (undergoes a heating process that kills the bacteria).
Tuberculosis (TB) is an infectious disease caused by bacteria whose scientific name is Mycobacterium tuberculosis. It was first isolated in 1882 by a German physician named Robert Koch who received the Nobel prize for this discovery.
TB most commonly affects the lungs but also can involve almost any organ of the body. Many years ago, this disease was referred to as "consumption" because without effective treatment, these patients often would waste away. Today, of course, tuberculosis usually can be treated successfully with antibiotics.
There is also a group of organisms referred to as atypical tuberculosis. These involve other types of bacteria that are in the Mycobacterium family. Often, these organisms do not cause disease and are referred to a "colonizers," because they simply live alongside other bacteria in our bodies without causing damage.
At times, these bacteria can cause an infection that is sometimes clinically like typical tuberculosis. When these atypical mycobacteria cause infection, they are often very difficult to cure.
Often, drug therapy for these organisms must be administered for one and a half to two years and requires multiple medications.
Some cases of pneumonia are contracted by breathing in small droplets that contain the organisms that can cause pneumonia. These droplets get into the air when a person infected with these germs coughs or sneezes. In other cases, pneumonia is caused when bacteria or viruses that are normally present in the mouth, throat, or nose inadvertently enter the lung.
During sleep, it is quite common for people to aspirate secretions from the mouth, throat, or nose. Normally, the body's reflex response (coughing back up the secretions) and immune system will prevent the aspirated organisms from causing pneumonia.
However, if a person is in a weakened condition from another illness, a severe pneumonia can develop. People with recent viral infections, lung disease, heart disease, and swallowing problems, as well as alcoholics, drug users, and those who have suffered a stroke or seizure are at higher risk for developing pneumonia than the general population.
Once organisms enter the lungs, they usually settle in the air sacs of the lung where they rapidly grow in number. This area of the lung then becomes filled with fluid and pus as the body attempts to fight off the infection.
Pneumonia is an infection of one or both lungs which is usually caused by bacteria, viruses, or fungi. Prior to the discovery of antibiotics, one-third of all people who developed pneumonia subsequently died from the infection. Currently, over 3 million people develop pneumonia each year in the United States.
Over a half a million of these people are admitted to a hospital for treatment. Although most of these people recover, approximately 5% will die from pneumonia. Pneumonia is the sixth leading cause of death in the United States.
Avian influenza cannot be diagnosed by symptoms alone, so a laboratory test is required. Avian influenza is usually diagnosed by collecting a swab from the nose or throat during the first few days of illness. This swab is then sent to a laboratory, where they will either look for avian influenza virus using a molecular test, or they will try to grow the virus.
Growing avian influenza viruses should only be done in laboratories with high levels of protection. If it is late in the illness, it may be difficult to find an avian influenza virus directly using these methods. If this is the case, it may still be possible to diagnose avian influenza by looking for evidence of the body's response to the virus.
This is not always an option because it requires two blood specimens (one taken during the first few days of illness and another taken some weeks later), and it can take several weeks to verify the results.
The flu is highly infectious and is a serious viral respiratory infection. Whereas with other viral respiratory infections the symptoms usually are mild and most people can continue working or going to school while ill, with the flu, the symptoms are severe and prolonged and cause individuals to miss days of work or school. The infection stresses the body.
In addition, superinfections may occur. Superinfections are bacterial infections that occur on top of a respiratory infection. Bacterial respiratory infections also are a serious type of infection, and the simultaneous viral and bacterial infection can overwhelm the function of the lungs and the body.
Among the elderly and the very young, it can cause death. Because of its infectiousness, morbidity (severity of symptoms and time lost from work or school), and the potential for death, it is important to prevent the flu by vaccination.
Although there are medications to treat the flu, they are expensive, not as effective as vaccination, and need to be started within 24-48 hours of the start of symptoms.
The flu (or common flu) is a viral infection that is spread from person to person in secretions of the nose and lungs, for example when sneezing. Medically it is referred to as influenza. Flu is a respiratory infection, that is, an infection that develops primarily in the lungs.
Respiratory infections caused by other viruses often are called flu, but this is incorrect. Influenza usually causes higher fever, more malaise, and severe body aches. Although other viruses may cause these symptoms, they do so less commonly.
The flu is a common illness. Every year in the United States, on average:
* 5% to 20% of the population gets the flu,
* more than 200,000 people are hospitalized from flu complications, and
* about 36,000 people die from the flu
Although uncomplicated influenza-like illness (fever, cough or sore throat) has been reported in many cases, mild respiratory illness (nasal congestion, rhinorrhea) without fever and occasional severe disease also has been reported.
Other symptoms reported with swine influenza A virus infection include vomiting, diarrhea, myalgia, headache, chills, fatigue, and dyspnea. Conjunctivitis is rare, but has been reported. Severe disease (pneumonia, respiratory failure) and fatal outcomes have been reported with swine influenza A virus infection.
The potential for exacerbation of underlying chronic medical conditions or invasive bacterial infection with swine influenza A virus infection should be considered.
The swine influenza A (H1N1) virus that has infected humans in the U.S. and Mexico is a novel influenza A virus that has not previously been identified in North America.
This virus is resistant to the antiviral medications amantadine (Symmetrel) and rimantadine (Flumadine), but is sensitive to oseltamivir (Tamiflu) and zanamivir (Relenza).
Investigations of these cases suggest that on-going human-to-human swine influenza A (H1N1) virus is occurring.
Diarrhea can be defined in absolute or relative terms based on either the frequency of bowel movements or the consistency (looseness) of stools.
Frequency of bowel movements. Absolute diarrhea is having more bowel movements than normal. Thus, since among healthy individuals the maximum number of daily bowel movements is approximately three, diarrhea can be defined as any number of stools greater than three.
Relative diarrhea is having more bowel movements than usual.
Thus, if an individual who usually has one bowel movement each day begins to have two bowel movements each day, then diarrhea is present-even though there are not more than three bowel movements a day, that is, there is not absolute diarrhea.
Consistency of stools. Absolute diarrhea is more difficult to define on the basis of the consistency of stool because the consistency of stool can vary considerably in healthy individuals depending on their diets. Thus, individuals who eat large amounts of vegetables will have looser stools than individuals who eat few vegetables.
Stools that are liquid or watery are always abnormal and considered diarrheal. Relative diarrhea is easier to define based on the consistency of stool. Thus, an individual who develops looser stools than usual has diarrhea--even though the stools may be within the range of normal with respect to consistency.
Diarrhea is an increase in the frequency of bowel movements or a decrease in the form of stool (greater looseness of stool). Although changes in frequency of bowel movements and looseness of stools can vary independently of each other, changes often occur in both.
Diarrhea needs to be distinguished from four other conditions. Although these conditions may accompany diarrhea, they often have different causes and different treatments than diarrhea.
These other conditions are:
1. incontinence of stool, which is the inability to control (delay) bowel movements until an appropriate time, for example, until one can get to the toilet
2. rectal urgency, which is a sudden urge to have a bowel movement that is so strong that if a toilet is not immediately available there will be incontinence
3. incomplete evacuation, which is a sensation that another bowel movement is necessary soon after a bowel movement, yet there is difficulty passing further stool the second time
4. bowel movements immediately after eating a meal
In 1981, homosexual men with symptoms of a disease that now are considered typical of the acquired immunodeficiency syndrome (AIDS) were first described in Los Angeles and New York. The men had an unusual type of lung infection (pneumonia) called Pneumocystis carinii (now known as Pneumocystis jiroveci) pneumonia (PCP) and rare skin tumors called Kaposi's sarcomas.
The patients were noted to have a severe reduction in a type of cell in the blood that is an important part of the immune system, called CD4 cells. These cells, often referred to as CD4 T cells, help the body fight infections.
Shortly thereafter, this disease was recognized throughout the United States, Western Europe, and Africa. In 1983, researchers in the United States and France described the virus that causes AIDS, now known as the human immunodeficiency virus (HIV) and belonging to the group of viruses called retroviruses.
In 1985, a blood test became available that measures antibodies to HIV that are the body's immune response to the HIV. This blood test remains the best method for diagnosing HIV infection. Recently, tests have become available to look for these same antibodies in blood and saliva, some providing results within 20 minutes of testing.