Selective serotonin reuptake inhibitors are medicines that relieve symptoms of depression. Selective serotonin reuptake inhibitors are used to treat serious, continuing depression that interferes with a person's ability to function. Like other antidepressant drugs, they help reduce the extreme sadness, hopelessness, and lack of interest in life that are typical in people with depression. Se…
Self-mutilation is a general term for a variety of forms of intentional self-harm without the wish to die. Cutting one's skin with razors or knives is the most common pattern of self-mutilation. Others include biting, hitting, or bruising oneself; picking or pulling at skin or hair; burning oneself with lighted cigarettes, or amputating parts of the body. Self-mutilation has become a major …
Semen analysis evaluates a man's sperm and semen. It is done to discover cause for infertility and to confirm success of vasectomy. Semen analysis is an initial step in investigating why a couple has been unable to conceive a child. Abnormalities of sperm and semen can cause male infertility. Semen is the thick yellow-white male ejaculate containing sperm. Sperm are the male sex cells that …
Seniors' health refers to the physical and mental conditions of senior citizens, those who are in their 60s and older. For a senior, the aging process and a person's lifestyle will affect health. People who maintain a healthy weight, exercise regularly, eat nutritionally, and don't smoke reduce the risk for many health conditions. This wellness allows people to live longer and…
Sensory integration disorder or dysfunction (SID) is a neurological disorder that results from the brain's inability to integrate certain information received from the body's five basic sensory systems. These sensory systems are responsible for detecting sights, sounds, smell, tastes, temperatures, pain, and the position and movements of the body. The brain then forms a combined pict…
Sepsis refers to a bacterial infection in the bloodstream or body tissues. This is a very broad term covering the presence of many types of microscopic diseasecausing organisms. Sepsis is also called bacteremia. Closely related terms include septicemia and septic syndrome. In the general population, the incidence of sepsis is two people in 10,000. Sepsis can originate anywhere bacteria can gain en…
Septic shock is a potentially lethal drop in blood pressure due to the presence of bacteria in the blood. Septic shock is a possible consequence of bacteremia, or bacteria in the bloodstream. Bacterial toxins, and the immune system response to them, cause a dramatic drop in blood pressure, preventing the delivery of blood to the organs. Septic shock can lead to multiple organ failure including res…
Septoplasty is a surgical procedure to correct the shape of septum of the nose. The nasal septum is the separation between the two nostrils. In adults, the septum is composed partly of cartilage and partly of bone. Septoplasty is performed to correct a crooked (deviated) or dislocated septum, often as part of plastic surgery of the nose (rhinoplasty). The nasal septum has three functions: to suppo…
Serum sickness is a type of delayed allergic response, appearing four to 10 days after exposure to some antibiotics or antiserum, the portion of serum that contains anti-bodies, such as gamma globulin, which may be given to provide immunization against some diseases. Serum sickness is very similar to an allergic reaction. The patient's immune system recognizes the proteins in the drug or an…
Severe combined immunodeficiency (SCID) is the most serious human immunodeficiency disorder(s). It is a group of congenital disorders in which both the humoral part of the patient's immune system and the cells involved in immune responses fail to work properly. Children with SCID are vulnerable to recurrent severe infections, retarded growth, and early death. SCID is thought to affect betwe…
Also known as sex reassignment surgery, sex change surgery is a procedure that changes genital organs from one gender to another. There are two reasons to alter the genital organs from one sex to another. In both cases, technical considerations favor successful conversion to a female rather than a male. Newborns with ambiguous organs will almost always be assigned to the female sex, unless the pen…
Sex hormones tests measure levels of the sex hormones, including estrogen, progesterone, and testosterone. The sex hormone tests are ordered to determine if secretion of these hormones is normal. Estrogen fraction test is done to evaluate sexual maturity, menstrual problems, and fertility problems in females. This test may also be used to test for tumors that excrete estrogen. In pregnant women it…
Sex therapy is the treatment of sexual dysfunction. Sex therapy utilizes various techniques in order to relieve sexual dysfunction commonly caused by premature ejaculation or sexual anxiety and to improve the sexual health of the patient. Sexual dysfunction conjures up feelings of guilt, anger, insecurity, frustration, and rejection. Therapy is slow and requires open communication and understandin…
Sexual dysfunction is broadly defined as the inability to fully enjoy sexual intercourse. Specifically, sexual dysfunctions are disorders that interfere with a full sexual response cycle. These disorders make it difficult for a person to enjoy or to have sexual intercourse. While sexual dysfunction rarely threatens physical health, it can take a heavy psychological toll, bringing on depression, an…
Sexual perversions are conditions in which sexual excitement or orgasm is associated with acts or imagery that are considered unusual within the culture. To avoid problems associated with the stigmatization of labels, the neutral term "paraphilia," derived from Greek roots meaning "alongside of" and "love," is used to describe what used to be called sexual…
Sexually transmitted disease (STD) is a term used to describe more than 20 different infections that are transmitted through exchange of semen, blood, and other body fluids; or by direct contact with the affected body areas of people with STDs. Sexually transmitted diseases are also called venereal diseases. The Centers for Disease Control and Prevention (CDC) has reported that 85% of the most pre…
Shaken baby syndrome (SBS) is a collective term for the internal head injuries a baby or young child sustains from being violently shaken. Shaken baby syndrome was first described in medical literature in 1972. Physicians earlier labeled these injuries as accidental, but as more about child abuse became known, more cases of this syndrome were properly diagnosed. Every year, nearly 50,000 children …
Shiatsu is a manipulative therapy developed in Japan and incorporating techniques of anma (Japanese traditional massage), acupressure, stretching, and Western massage. Shiatsu involves applying pressure to special points or areas on the body in order to maintain physical and mental well being, treat disease, or alleviate discomfort. This therapy is considered holistic because it attempts to treat …
Shigellosis is an infection of the intestinal tract by a group of bacteria called Shigella. The bacteria is named in honor of Shiga, a Japanese researcher, who discovered the organism in 1897. The major symptoms are diarrhea, abdominal cramps, fever, and severe fluid loss (dehydration). Four different groups of Shigella can affect humans; of these, S. dysenteriae generally produces the most severe…
Shingles, also called herpes zoster, gets its name from both the Latin and French words for belt or girdle and refers to girdle-like skin eruptions that may occur on the trunk of the body. The virus that causes chickenpox, the varicella zoster virus (VSV), can become dormant in nerve cells after an episode of chickenpox and later reemerge as shingles. Initially, red patches of rash develop into bl…
Shock is a medical emergency in which the organs and tissues of the body are not receiving an adequate flow of blood. This deprives the organs and tissues of oxygen (carried in the blood) and allows the buildup of waste products. Shock can result in serious damage or even death. There are three stages of shock: Stage I (also called compensated, or nonprogressive), Stage II (also called decompensat…
Shortness of breath, or dyspnea, is a feeling of difficult or labored breathing that is out of proportion to the patient's level of physical activity. It is a symptom of a variety of different diseases or disorders and may be either acute or chronic. The experience of dyspnea depends on its severity and underlying causes. The feeling itself results from a combination of impulses relayed to …
Shy-Drager syndrome (SDS) is a rare condition that causes progressive damage to the autonomic nervous system. The autonomic nervous system controls vital involuntary body functions such as heart rate, breathing, and intestinal, urinary, and sexual functions. The autonomic nervous system also controls skin and body temperature, and how the body responds to stress. Shy-Drager syndrome leads to dizzi…
Sick sinus syndrome is a disorder of the sinus node of the heart, which regulates heartbeat. With sick sinus syndrome, the sinus node fails to signal properly, resulting in changes in the heart rate. The sinus node in the heart functions as the heart's pacemaker, or beat regulator. In sick sinus syndrome, patients normally will experience bradycardia, or slowed heart rate. Also, it is not u…
Sickle cell disease describes a group of inherited blood disorders characterized by chronic anemia, painful events, and various complications due to associated tissue and organ damage. The most common and well-known type of sickle cell disease is sickle cell anemia, also called SS disease. All types of sickle cell disease are caused by a genetic change in hemoglobin, the oxygen-carrying protein in…
Sideroblastic anemia is a term used to describe a group of rare blood disorders characterized by the bone marrow's inability to manufacture normal red blood cells. Named for the Greek words for iron and germ, sideroblastic anemia is one of the principal types of iron-utilization anemia. Abnormal, iron-saturated red cells are present in the blood of people who have this disease. Although the…
Sigmoidoscopy is a procedure by which a doctor inserts either a short and rigid or slightly longer and flexible fiber-optic tube into the rectum to examine the lower portion of the large intestine (or bowel). Sigmoidoscopy is used most often in screening for colorectal cancer or to determine the cause of rectal bleeding. It is also used for the diagnosis of inflammatory bowel disease and other ben…
Sildenafil citrate (Viagra) is a medication used to treat erectile dysfunction (ED), or impotence, in men. Viagra treats erectile dysfunction, the inability to achieve and/or maintain an erection of the penis that is adequate for sexual intercourse. Ten to fifteen million men in the United States suffer from ED, and by age 65, up to 25% of men have experienced impotence problems. Erectile dysfunct…
Silicosis is a progressive disease that belongs to a group of lung disorders called pneumoconioses. Silicosis is marked by the formation of lumps (nodules) and fibrous scar tissue in the lungs. It is the oldest known occupational lung disease, and is caused by exposure to inhaled particles of silica, mostly from quartz in rocks, sand, and similar substances. It is estimated that there are two mill…
An endoscope is a narrow flexible tube which contains an optical device like a telescope or magnifying lens with a bright light. In sinus endoscopy, the endoscope is inserted into the nose, and the interior of the nasal passages, sinuses, and throat is examined. Sinus endoscopy is used to help diagnose structural defects, infection or damage to the sinuses, or structures in the nose and throat. It…
Sinusitis refers to an inflammation of the sinuses, airspaces within the bones of the face. Sinusitis is most often due to an infection within these spaces. The sinuses are paired air pockets located within the bones of the face. They are: The sinuses are connected with the nose. They are lined with the same kind of skin found elsewhere within the respiratory tract. This skin has tiny little hairs…
Situs inversus is a condition in which the organs of the chest and abdomen are arranged in a perfect mirror image reversal of the normal positioning. Normal human development results in an asymmetrical arrangement of the organs within the chest and abdomen. Typically, the heart lies on the left side of the body (levocardia), the liver and spleen lie on the right, and the lung on the left has two l…
A sitz bath (also called a hip bath) is a type of bath in which only the hips and buttocks are soaked in water or saline solution. Its name comes from the German verb "sitzen," meaning "to sit." A sitz bath is used for patients who have had surgery in the area of the rectum, or to ease the pain of hemorrhoids, uterine cramps, prostate infections, painful ovaries, and/or…
Sjögren's syndrome is a disorder where the mouth and eyes become extremely dry. Sjögren's syndrome is often associated with other autoimmune disorders. Like other autoimmune disorders, Sjögren's syndrome occurs when the body's immune system mistakenly begins treating parts of the body as foreign invaders. While the immune cells should attack and kil…
A skin biopsy is a procedure in which a small piece of living skin is removed from the body for examination, usually under a microscope, to establish a precise diagnosis. Skin biopsies are usually brief, straightforward procedures performed by a skin specialist (dermatologist) or family physician. The word biopsy is taken from Greek words that mean "to view life." The term describes …
Non-melanoma skin cancer is a malignant growth of the external surface or epithelial layer of the skin. Skin cancer is the growth of abnormal cells capable of invading and destroying other associated skin cells. Skin cancer is often subdivided into either melanoma or non-melanoma. Melanoma is a dark-pigmented, usually malignant tumor arising from a skin cell capable of making the pigment melanin (…
A skin culture is a test that is done to identify the microorganism (bacteria, fungus, or virus) causing a skin infection and to determine the antibiotic or other treatment that will effectively treat the infection. Microorganisms can infect healthy skin, but more often they infect skin already damaged by an injury or abrasion. Skin infections are contagious and, if left untreated, can lead to ser…
Skin grafting is a surgical procedure by which skin or skin substitute is placed over a burn or non-healing wound to permanently replace damaged or missing skin or provide a temporary wound covering. Wounds such as third-degree burns must be covered as quickly as possible to prevent infection or loss of fluid. Wounds that are left to heal on their own can contract, often resulting in serious scarr…
Skin lesion removal employs a variety of techniques, from relatively simple biopsies to more complex surgical excisions, to remove lesions that range from benign growths to malignant melanoma. Sometimes the purpose of skin lesion removal is to excise an unsightly mole or other cosmetically unattractive skin growth. Other times, physicians will remove a skin lesion to make certain it is not cancero…
A skin lesion is a superficial growth or patch of the skin that does not resemble the area surrounding it. Skin lesions can be grouped into two categories: primary and secondary. Primary skin lesions are variations in color or texture that may be present at birth, such as moles or birthmarks, or that may be acquired during a person's lifetime, such as those associated with infectious diseas…
Skin pigmentation disorders are conditions that cause the skin to appear lighter or darker than normal, or blotchy and discolored. People of all races have skin pigmentation disorders. Some disorders, like albinism (which affects one out of every 17,000 people) are rare. Others, such as age spots, are very common. Skin pigmentation disorders occur because the body produces either too much or too l…
Skin resurfacing employs a variety of techniques to change the surface texture and appearance of the skin. Common skin resurfacing techniques include chemical peels, dermabrasion, and laser resurfacing. Skin resurfacing procedures may be performed for cosmetic reasons, such as diminishing the appearance of wrinkles around the mouth or eyes. They may also be used as a medical treatment, such as rem…
Skull x rays are performed to examine the nose, sinuses, and facial bones. These studies may also be referred to as sinus x rays. X-ray studies produce films, also known as radiographs, by aiming x rays at soft bones and tissues of the body. X-ray beams are similar to light waves, except their shorter wavelength allows them to penetrate dense substances, producing images and shadows on film. Docto…
Sleep apnea is a condition in which breathing stops for more than 10 seconds during sleep. Sleep apnea is a major, though often unrecognized, cause of daytime sleepiness. A sleeping person normally breathes continuously and uninterruptedly throughout the night. A person with sleep apnea, however, has frequent episodes (up to 400–500 per night) in which he or she stops breathing. This interr…
Sleep disorders are a group of syndromes characterized by disturbance in the patient's amount of sleep, quality or timing of sleep, or in behaviors or physiological conditions associated with sleep. There are about 70 different sleep disorders. To qualify for the diagnosis of sleep disorder, the condition must be a persistent problem, cause the patient significant emotional distress, and in…
Sleeping sickness (also called trypanosomiasis) is an infection caused by Trypanosoma protozoa; it is passed to humans through the bite of the tsetse fly. If left untreated, the infection progresses to death within months or years. Protozoa are single-celled organisms considered to be the simplest life form in the animal kingdom. The protozoa responsible for sleeping sickness are a variety that be…
A biopsy is a diagnostic procedure in which tissue or cells are removed from a part of the body and specially prepared for examination under a microscope. When the tissue involved is part of the small intestine, the procedure is called a small-intestine (or small-bowel) biopsy. The small-bowel biopsy is used to diagnose and confirm disease of the intestinal mucosa (the lining of the small intestin…
Smallpox is an infection caused by the virus called variola, a member of the poxvirus family. Throughout all of history, smallpox has been a greatly feared disease, responsible for huge epidemics worldwide, and the cause of great suffering and massive numbers of deaths. In 1980, the World Health Organization (WHO) announced that an extensive program of vaccination against the disease had resulted …
Smelling disorders are disturbances of the olfactory sense, which is known as the sense of smell. These nasal dysfunctions range from the total loss of smell (anosmia) to dysosmia, a distorted sense of smell. An awareness of how the olfactory system works is helpful for understanding how smelling disorders affect the sense of smell. People detect odors because sensory receptors located in the nose…
Smoke inhalation is breathing in the harmful gases, vapors, and particulate matter contained in smoke. Smoke inhalation typically occurs in victims or fire-fighters caught in structural fires. However, cigarette smoking also causes similar damage on a smaller scale over a longer period of time. People who are trapped in fires may suffer from smoke inhalation independent of receiving skin burns; ho…
Smoking is the inhalation of the smoke of burning tobacco encased in cigarettes, pipes, and cigars. Casual smoking is the act of smoking only occasionally, usually in a social situation or to relieve stress. A smoking habit is a physical addiction to tobacco products. Many health experts now regard habitual smoking as a psychological addiction, too, and one with serious health consequences. The U.…
Smoking cessation drugs are medicines that help people stop smoking cigarettes or using other forms of tobacco. The nicotine patch is a type of transepidermal patch designed to deliver nicotine, the addictive substance contained in cigarettes, directly through the skin and into the blood stream.The patch contains a drug reservoir sandwiched between a non-permeable back layer and a permeable ad…
Snoring is a sound generated during sleep when the roof of the mouth vibrates. Snoring is one symptom of a group of disorders known as sleep disordered breathing. It occurs when the soft palate, uvula, tongue, tonsils, and/or muscles in the back of the throat rub against each other and generate a vibrating sound during sleep. Twenty percent of all adults are chronic snorers, and 45% of normal adul…
The somatoform disorders are a group of mental disturbances placed in a common category on the basis of their external symptoms. These disorders are characterized by physical complaints that appear to be medical in origin but that cannot be explained in terms of a physical disease, the results of substance abuse, or by another mental disorder. In order to meet the criteria for a somatoform disorde…
Sore throat, also called pharyngitis, is a painful inflammation of the mucous membranes lining the pharynx. It is a symptom of many conditions, but most often is associated with colds or influenza. Sore throat may be caused by either viral or bacterial infections or environmental conditions. Most sore throats heal without complications, but they should not be ignored because some develop into seri…
South American blastomycosis is a potentially fatal, chronic fungus infection that occurs more often in men. The infection may affect different parts of the body, including the lungs or the skin, and may cause ulcers of the mouth, voicebox, and nose. South American blastomycosis occurs primarily in Brazil, although cases crop up in Mexico, Central America, or other parts of South America. It affec…
According to the American Speech-Language-Hearing Association (ASHA), a language disorder is an impairment in comprehension use of the spoken, written, or other symbol system. Speech disorders affect the language and mechanics, the content of speech, or the function of language in communication. Because speech disorders affect a person's ability to communicate effectively, every aspect of t…
Spina bifida is a serious birth abnormality in which the spinal cord is malformed and lacks its usual protective skeletal and soft tissue coverings. Spina bifida may appear in the body midline anywhere from the neck to the buttocks. In its most severe form, termed spinal rachischisis, the entire spinal canal is open, exposing the spinal cord and nerves. More commonly, the abnormality appears as a …
Spinal cord injury is damage to the spinal cord that causes loss of sensation and motor control. Approximately 10,000 new spinal cord injuries (SCIs) occur each year in the United States. About 250,000 people are currently affected. Spinal cord injuries can happen to anyone at any time of life. The typical patient, however, is a man between the ages of 19 and 26, injured in a motor vehicle acciden…
A spinal cord tumor is a benign or cancerous growth in the spinal cord, between the membranes covering the spinal cord, or in the spinal canal. A tumor in this location can compress the spinal cord or its nerve roots; therefore, even a noncancerous growth can be disabling unless properly treated. The spinal cord contains bundles of nerves that carry messages betweent the brain and the body. Becaus…
