Testicular torsion is the twisting of a testis (testicle) on its connection. The testes are suspended in the scrotum by a single bundle of tissues that also carries the blood supply to and from the testes. If the testicle rotates, the bundle kinks, and the blood supply is shut off. The resulting situation is an emergency because the testis will die within hours if the blood supply is not restored.…
Tetanus is a rare but often fatal disease that affects the central nervous system by causing painful muscular contractions. It begins when tetanus bacteria enter the body, usually through a wound or cut exposed to contaminated soil. Tetanus is easily preventable through vaccination. Tetanus is rare in the United States, with nearly all cases occurring in adults who were not vaccinated as children.…
Tetracyclines are medicines that kill certain infection-causing microorganisms. Tetracyclines are called "broad-spectrum" antibiotics, because they can be used to treat a wide variety of infections. Physicians may prescribe these drugs to treat eye infections, pneumonia, gonorrhea, Rocky Mountain spotted fever, urinary tract infections, and other infections caused by bacteria. The me…
Tetralogy of Fallot is a common syndrome of congenital heart defects. The heart is two pumps in one. The ventricle on the left side pumps blood full of oxygen through the body; the ventricle on the right side pumps the same blood through the pulmonary artery to the lungs to take up oxygen. The left ventricle operates at pressures about four times as high as the right ventricle. Blood is supposed t…
Thalassemia describes a group of inherited disorders characterized by reduced or absent amounts of hemoglobin, the oxygen-carrying protein inside the red blood cells. There are two basic groups of thalassemia disorders: alpha thalassemia and beta thalassemia. These conditions cause varying degrees of anemia, which can range from insignificant to life threatening. All types of thalassemias are cons…
A thallium heart scan is a test using a special camera and a small amount of radioactive substance injected into the bloodstream to make an image of the blood flow to the heart. A thallium heart scan is used to evaluate the blood supply to the heart muscle. It can identify areas of the heart that may have a poor blood supply as a result of damage from a previous heart attack or blocked coronary ar…
The thematic apperception test (TAT) is a projective personality test that was designed at Harvard in the 1930s by Christiana D. Morgan and Henry A. Murray. Along with the MMPI and the Rorschach, the TAT is one of the most widely used psychological tests. A projective test is one in which a person's patterns of thought, attitudes, observational capacity, and emotional responses are evaluate…
Bathing the skin in a variety of preparations in order to remove crusts, scales, and old medications or to relieve inflammation and itching is called a therapeutic bath. Baths or soaks (balneotherapy) are an easy way to treat a variety of skin disorders involving large areas of the skin. They relieve general aches and pains and can ease dry or oily, inflamed or itchy skin. Hot baths are relaxing a…
Therapeutic touch, or TT, is a noninvasive method of healing that was derived from an ancient laying-on of hands technique. In TT, the practitioner alters the patient's energy field through an energy transfer that moves from the hands of the practitioner to the patient. As the study progressed, Kunz began teaching Krieger how to heal, based on her perceptions of Estebany's healing te…
Also known as pleural fluid analysis, thoracentesis is a procedure that removes fluid or air from the chest through a needle or tube. The lungs are lined on the outside with two thin layers of tissue called pleura. The space between these two layers is called the pleural space. Normally, there is only a small amount of lubricating fluid in this space. Liquid and/or air accumulates in this space be…
Thoracic outlet syndromes are a group of disorders that cause pain and abnormal nerve sensations in the neck, shoulder, arm, and/or hand. The thoracic outlet is an area at the top of the rib cage, between the neck and the chest. Several anatomical structures pass through this area, including the esophagus, trachea, and nerves and blood vessels that lead to the arm and neck region. The area contain…
Thoracic surgery is the repair of organs located in the thorax, or chest. The thoracic cavity lies between the neck and the diaphragm, and contains the heart and lungs (cardiopulmonary system), the esophagus, trachea, pleura, mediastinum, chest wall, and diaphragm. Thoracic surgery repairs diseased or injured organs and tissues in the thoracic cavity. General thoracic surgery deals specifically wi…
Thoracoscopy is the insertion of an endoscope, a narrow-diameter tube with a viewing mirror or camera attachment, through a very small incision (cut) in the chest wall. Thoracoscopy makes it possible for a physician to examine the lungs or other structures in the chest cavity, without making a large incision. It is an alternative to thoracotomy (opening the chest cavity with a large incision). Man…
Threadworm infection is an intestinal disease, which occasionally spreads to the skin, caused by a type of parasitic roundworm (helminth). In untreated patients, the disease has a high rate of reinfection caused by worms already present in the body. This type of disease recurrence is called autoinfection. Because of autoinfection, threadworms can remain inside humans for as long as 45 years after …
A throat culture is a technique for identifying disease bacteria in material taken from the throat. Most throat cultures are done to rule out infections caused by beta-hemolytic streptococci, which cause strep throat. Hemolytic means that these streptococci destroy red blood cells. The primary purpose of a throat culture is identification of the specific organisms that cause strep throat. These or…
Thrombocytopenia is an abnormal drop in the number of blood cells involved in forming blood clots. These cells are called platelets. Thrombocytopenia is a blood disease characterized by an abnormally low number of platelets in the bloodstream. The normal amount of platelets is usually between 150,000 and 450,000 cells per microliter of blood. A microliter is an amount equal to one one-millionth of…
Thrombocytosis is a blood disorder in which the body produces a surplus of platelets (thrombocytes). Thrombocytosis is an abnormally increased number of platelets in the blood. Platelets are blood cells that stick together, helping blood to clot. Thrombocytosis is a condition that may have many causes. Throbocytosis is classified as one of two types. Secondary thrombocytosis can be traced to anoth…
Thrombolytic therapy is the use of drugs that dissolve blood clots. When a blood clot forms in a blood vessel, it may cut off or severely reduce blood flow to parts of the body that are served by that blood vessel. This can cause serious damage to those parts of the body. If the clot forms in an artery that supplies blood to the heart, for example, it can cause a heart attack. A clot that cuts off…
Thrombophlebitis is the inflammation of a vein with blood clot formation inside the vein at the site of inflammation. Thrombophlebitis is also known as phlebitis, phlebothrombosis, and venous thrombosis. There are two parts to thrombophlebitis, inflammation of a vein and blood clot formation. If the inflammation component is minor, the disease is usually called venous or phlebothrombosis. Thrombop…
Thymomas are the most common tumor of the thymus. The thymus is located in the upper chest just below the neck. It is a small organ that produces certain types of white blood cells before birth and during childhood. These white blood cells are called lymphocytes and are an important part of the body's immune system. Once released from the thymus, lymphocytes travel to lymph nodes where they…
The thyroid biopsy is a procedure in which a sample of thyroid tissue is withdrawn for laboratory examination. The sample can be withdrawn through a needle or a surgical incision may be made to obtain a piece of thyroid tissue. The test is generally performed when a lump or a nodule is detected in the thyroid. The test may also be ordered if the thyroid gland is enlarged and the cause is not appar…
Thyroid cancer is a disease in which the cells of the thyroid gland become abnormal, grow uncontrollably, and form a mass of cells called a tumor. Thyroid cancer is grouped into four types based on how its cells appear under a microscope. The types are papillary, follicular, medullary and anaplastic thyroid cancers. They grow at different rates and can spread to other parts of the body if left unt…
Thyroid function tests are blood tests used to evaluate how effectively the thyroid gland is working. These tests include the thyroid-stimulating hormone test (TSH), the thyroxine test (T4), the triiodothyronine test (T3), the thyroxine-binding globulin test (TBG), the triiodothyro-nine resin uptake test (T3RU), and the long-acting thyroid stimulator test (LATS). Thyroid function tests are used to…
Thyroid hormones are artificially made hormones that make up for a lack of natural hormones produced by the thyroid gland. The thyroid gland, a butterfly-shaped structure in the lower part of the neck, normally produces a hormone called thyroxine. This hormone controls the rate of metabolism—all the physical and chemical processes that occur in cells to allow growth and maintain body functi…
A thyroid nuclear medicine scan is a diagnostic procedure to evaluate the thyroid gland, which is located in the front of the neck and controls the body's metabolism. A radioactive substance that concentrates in the thyroid is taken orally or injected into a vein (intravenously), or both. A special camera is used to take an image of the distribution of the radioactive substance in and aroun…
Thyroid ultrasound is an imaging technique used for diagnosing suspected thyroid disease. It uses harmless, high-frequency sound waves to form an image. The sound waves are reflected by thyroid tissue to form a picture of internal structures. It is not invasive and involves no radiation. The thyroid gland is an organ located in front of the neck. It plays an important role in controlling the body&…
Thyroidectomy is a surgical procedure in which all or part of the thyroid gland is removed. The thyroid gland is located in the forward part of the neck (anterior) just under the skin and in front of the Adam's apple. All or part of the thyroid gland may be removed to correct a variety of abnormalities of the gland. If the patient has a goiter (an enlargement of the thyroid gland, causing a…
Thyroiditis is inflammation of the thyroid gland, a butterfly-shaped organ next to the windpipe. The thyroid is the largest gland in the neck. It produces, secretes, and stores thyroxine (T4), a hormone that influences the metabolism of just about every body process. When the thyroid gland is functioning properly, hormone release is carefully regulated. When bacteria or viruses invade and inflame …
The tilt table test is a test in which a patient is positioned in a supine position and brought to a predetermined angle or angles from the horizontal position. Such positioning helps to determine the cause of any decrease in oxygen to the brain. Different types of drugs may also used in the testing process. The purpose of the tilt table test is to help determine appropriate therapy for individual…
Tinnitus is hearing ringing, buzzing, or other sounds without an external cause. Patients may experience tinnitus in one or both ears or in the head. Tinnitus affects as many as 40 million adults in the United States. It is defined as either objective or subjective. In objective tinnitus, the doctor can hear the sounds, as well as the patient. Objective tinnitus is typically caused by tumors, turb…
Tissue typing is a group of procedures that determines the type of histocompatibility antigens on a person's cells or tissues. This procedure is typically used prior to transplantation of tissues or organs. Tissue typing is done prior to transplantation to ensure as close a match as possible between the donor and the recipient. If the histocompatibility antigens do not match well, there is …
Tonsillectomy and adenoidectomy (T & A) are surgical procedures to remove the tonsils from the back of the mouth or adenoids from the back of the nasal cavity—both are are part of the lymphatic system, which is responsible for fighting infection. These operations are often performed together and are usually done on children. T & As are the most common childhood operations. Ton…
Tonsillitis is an infection and swelling of the tonsils, which are oval-shaped masses of lymph gland tissue located on both sides of the back of the throat. The tonsils normally help to prevent infections. They act like filters to trap bacteria and viruses entering The palatine, lingual, and pharyngeal tonsils. (Illustration by Hans & Cassady, Inc.) the body through the mouth and sin…
Tooth decay, which is also called dental cavities or dental caries, is the destruction of the outer surface (enamel) of a tooth. Decay results from the action of bacteria that live in plaque, which is a sticky, whitish film formed by a protein in saliva (mucin) and sugary substances in the mouth. The plaque bacteria sticking to tooth enamel use the sugar and starch from food particles in the mouth…
Tooth extraction is the removal of a tooth from its socket in the bone. Extraction is performed for positional, structural, or economic reasons. Teeth are often removed because they are impacted. Teeth become impacted when they are prevented from growing into their normal position in the mouth by gum tissue, bone, or other teeth. Impaction is a common reason for the extraction of wisdom teeth. Ext…
A tooth restoration is any artificial substance or structure that replaces missing teeth or part of a tooth in order to protect the mouth's ability to eat, chew, and speak. Restorations include fillings, inlays, crowns, bridges, partial and complete dentures, and dental implants. Restorations have somewhat different purposes depending on their extensiveness. Fillings, inlays, and crowns are…
A toothache is any pain or soreness within or around a tooth, indicating inflammation and possible infection. A toothache may feel like a sharp pain or a dull ache. The tooth may be sensitive to pressure, heat, cold, or sweets. In cases of severe pain, identifying the problem tooth is often difficult. Any patient with a toothache should see a dentist at once for diagnosis and treatment. Most tooth…
The TORCH test, which is sometimes called the TORCH panel, belongs to a category of blood tests called infectious-disease antibody titer tests. This type of blood test measures the presence of antibodies (protein molecules produced by the human immune system in response to a specific disease agent) and their level of concentration in the blood. The name of the test comes from the initial letters o…
Torticollis (cervical dystonia or spasmodic torticollis) is a type of movement disorder in which the muscles controlling the neck cause sustained twisting or frequent jerking. In torticollis, certain muscles controlling the neck undergo repetitive or sustained contraction, causing the neck to jerk or twist to the side. Cervical dystonia causes forward twisting, and is called antecollis. Backward t…
Tourette syndrome (TS) is an inherited disorder of the nervous system, characterized by a variable expression of unwanted movements and noises (tics). The first references in the literature to what might today be classified as Tourette syndrome largely describe individuals who were wrongly believed to be possessed by the devil. In 1885 Gilles de la Tourette, a French neurologist, provided the firs…
Toxic epidermal necrolysis is a rare condition that causes large portions of the epidermis, the skin's outermost layer, to detach from the layers of skin below. A reaction to a medication is the primary cause. Toxic epidermal necrolysis (TEN) begins with fever, cough, and other nonspecific symptoms, and is soon followed by purplish, bloody-looking lesions on the skin and mucous membranes. T…
Toxic shock syndrome (TSS) is an uncommon, but potentially serious, illness that occurs when poisonous substances (toxins) produced by certain bacteria enter the bloodstream. The toxins cause a type of blood poisoning caused by staphylococcal, or less commonly streptococcal, infections in the lungs, throat, skin or bone, or from injuries. Women using super-absorbent tampons during menstruation wer…
Toxoplasmosis is an infectious disease caused by the one-celled protozoan parasite Toxoplasma gondii. Although most individuals do not experience any symptoms, the disease can be very serious, and even fatal, in individuals with weakened immune systems. Toxoplasmosis is caused by a one-celled protozoan parasite known as Toxoplasma gondii. Cats, the primary carriers of the organism, become infected…
Trabeculectomy is a surgical procedure that removes part of the trabeculum in the eye to relieve pressure caused by glaucoma. Glaucoma is a disease that injures the optic nerve, causing progressive loss of vision. Presently, glaucoma is a major cause of blindness in the United States If caught early, glaucoma-related blindness is easily prevented, However, since it does not produce symptoms until …
Tracheoesophageal fistula (TEF) is commonly a birth defect, with the trachea connected to the esophagus. In most cases, the esophagus is discontinuous, causing immediate feeding difficulties. TEFs may develop in adult life, secondary to the invasion of cancer in the area. In addition, TEFs may be deliberately constructed with surgery to aid talking in a patient who has the larynx removed (a laryng…
A tracheotomy is a surgical procedure in which a cut or opening is made in the windpipe (trachea). The surgeon inserts a tube into the opening to bypass an obstruction, allow air to get to the lungs, or remove secretions. The term tracheostomy is sometimes used interchangeably with tracheotomy. Strictly speaking, however, tracheostomy usually refers to the opening itself while a tracheotomy is the…
Trachoma, which is also called granular conjunctivitis or Egyptian ophthalmia, is a contagious, chronic inflammation of the mucous membranes of the eyes, caused by Chlamydia trachomatis. It is characterized by swelling of the eyelids, sensitivity to light, and eventual scarring of the conjunctivae and corneas of the eyes. Trachoma is a major cause of blindness in the world. It is found in the Far …
Traction is the use of a pulling force to treat muscle and skeleton disorders. Traction is usually applied to the arms and legs, the neck, the backbone, or the pelvis. It is used to treat fractures, dislocations, and long-duration muscle spasms, and to prevent or correct deformities. Traction can either be short-term, as at an accident scene, or long-term, when it is used in a hospital setting. Tr…
Traditional Chinese medicine (TCM) is an ancient and still very vital holistic system of health and healing, based on the notion of harmony and balance, and employing the ideas of moderation and prevention. TCM is a complete system of health-care with its own unique theories of anatomy, health, and treatment. It emphasizes diet and prevention and using acupuncture, herbal medicine, massage, and ex…
Trager psychophysical integration therapy, also known as the Tragerwork system of physical integration, is a combination of hands-on tissue mobilization, relaxation, and movement reeducation called Mentastics. The underlying principle of psychophysical integration is that clients learn to be lighter, easier, and freer by experiencing lightness, ease, and freedom of movement in their bodies. The Tr…
Transcranial Doppler ultrasonography is a noninvasive method of analyzing blood flow in the brain. The blood that flows through the brain distributes nutrients to the brain and removes wastes. This flow maintains the high rate of metabolism necessary for the brain to function. Restrictions in blood flow may occur from vessel narrowing (stenosis), clot formation (thrombosis), blockage (embolism), o…
Transesophageal echocardiography is a diagnostic test using an ultrasound device that is passed into the esophagus of the patient to create a clear image of the heart muscle and other parts of the heart. A tube with a device called a transducer is passed down into the patient's throat and into the esophagus (the food tube that connects the mouth to the stomach). The transducer directs ultra…
The process of transferring whole blood or blood components from one person (donor) to another (recipient). Transfusions are given to restore lost blood, to improve clotting time, and to improve the ability of the blood to deliver oxygen to the body's tissues. For donors, the process of giving blood is very safe. Only sterile equipment is used and there is no chance of catching an infection…
Transhepatic biliary catheterization is a surgical procedure during which a catheter is inserted into the bile duct to relieve an obstruction. Bile is a fluid made in the liver and stored in the gall bladder. The function of bile is to break down fats during digestion. When fatty foods move into the intestine, bile is released from the gall bladder, travels through the bile duct, and enters the fi…
A transient ischemic attack, or TIA, is often described as a mini-stroke. Unlike a stroke, however, the symptoms can disappear within a few minutes. TIAs and strokes are both caused by a disruption of the blood flow to the brain. In TIAs and most strokes, this disruption is caused by a blood clot blocking one of the blood vessels leading to the brain. The blockage produces symptoms such as sudden …
Transposition of the great arteries is a birth defect causing a fatal condition in which there is a reversal, or switch, in the truncal connections of the two main (great) blood vessels to the heart, the aorta and pulmonary artery. There are two great arteries, the pulmonary artery and the aorta. Normally, the pulmonary artery carries blood from the right ventricle to the lungs. The aorta carries …
Transurethral bladder resection is a surgical procedure, performed under sedation or anesthesia, with a lighted tube inserted through the urethra (the small tube-like structure that allows urine to empty from the bladder), into the bladder. It plays both a diagnostic and therapeutic role in the treatment of bladder cancers. Tranurethral resection is the initial form of treatment for bladder cancer…
Transverse myelitis (TM) is an uncommon neurological syndrome caused by inflammation (a protective response which includes swelling, pain, heat, and redness) of the spinal cord, characterized by weakness, back pain, and bowel and bladder problems. It affects one to five persons per million. TM affects the entire thickness of the spinal cord, producing both sensory and movement problems. It is beli…
Traumatic amputation is the accidental severing of some or all of a body part. A complete amputation totally detaches a limb or appendage from the rest of the body. In a partial amputation, some soft tissue remains attached to the site. Trauma is the second leading cause of amputation in the United States. About 30,000 traumatic amputations occur in this country every year. Four of every five trau…
The occurrence of multiple loose bowel movements in someone traveling to an area outside of their usual surroundings (usually from temperate industrialized regions to tropical areas), is known as traveler's diarrhea (TD). The cause is almost always due to a bacterial or viral infection, acquired through ingesting contaminated food or water. It is estimated that anywhere from 20–50% o…
