Conditions & Diseases, SéG-VON
Whether we like it or not, living things are susceptible to any number of illnesses and conditions that can threaten or harm the health of those afflicted. Bacteria, viruses, and other microbiological agents are obvious challenges to health. Human disease may be acute, chronic, malignant, or benign, and it is usually indicated by signs and symptoms such as fever or vomiting. Additionally, diseases may be communicable (contagious) or noncommunicable; of the latter, the four major types identified by the World Health Organization are cancer, cardiovascular disease, chronic respiratory disease, and diabetes mellitus.
Conditions & Diseases Encyclopedia Articles By Title
Séguin, Edouard
Edouard Séguin was a French-born American psychiatrist who pioneered modern educational methods for teaching the......
T4 Program
T4 Program, Nazi German effort—framed as a euthanasia program—to kill incurably ill, physically or mentally disabled,......
tachycardia
tachycardia, a heart rate of more than 100 beats per minute. Tachycardia occurs normally during and after exercise......
taravana syndrome
taravana syndrome, form of neurological decompression sickness that is most frequently seen in breath-hold divers.......
tardive dyskinesia
tardive dyskinesia, drug-induced condition characterized by repetitive involuntary movements, particularly in the......
Taussig, Helen Brooke
Helen Brooke Taussig was an American physician recognized as the founder of pediatric cardiology, best known for......
Tay-Sachs disease
Tay-Sachs disease, hereditary metabolic disorder that causes progressive mental and neurologic deterioration and......
teetotalism
teetotalism, the practice or promotion of total abstinence from alcoholic drinks. It became popular as part of......
temperature stress
temperature stress, physiological stress induced by excessive heat or cold that can impair functioning and cause......
tendinitis
tendinitis, inflammation of the sheaths of the tendons. These sheaths are composed of thin, filmy tissue that permits......
tennis elbow
tennis elbow, an injury characterized by pain at the lateral (outer) aspect of the elbow. The patient may also......
teratoma
teratoma, rare tumor that originates from remnants of germ cells (the precursors of eggs and sperm) or germ layers......
testicular cancer
testicular cancer, disease characterized by uncontrolled growth of cells within the testis, the reproductive organ......
tetanus
tetanus, acute infectious disease of humans and other animals, caused by toxins produced by the bacillus Clostridium......
tetany
tetany, condition characterized by rhythmic cramping of the muscles of the hands and feet, muscle twitching, and......
thalassemia
thalassemia, group of blood disorders characterized by a deficiency of hemoglobin, the blood protein that transports......
The U.S. Opioid Epidemic
Since 1999, the death rate from opioid drug overdose in the United States has been on the rise. The rate nearly......
theileriasis
theileriasis, any of a group of livestock diseases caused by protozoan parasites of the genus Theileria (Gonderia),......
thoracic outlet syndrome
thoracic outlet syndrome (TOS), name given for a spectrum of symptoms caused by compression of the brachial nerve......
thoracic squeeze
thoracic squeeze, compression of the lungs and thoracic (chest) cavity that occurs during a breath-holding dive......
thrombocytopathy
thrombocytopathy, any of several blood disorders characterized by dysfunctional platelets (thrombocytes), which......
thrombocytopenia
thrombocytopenia, abnormally low number of platelets (thrombocytes) in the circulation. Normal platelet counts......
thrombophlebitis
thrombophlebitis, inflammation of a vein coupled with formation of a blood clot (thrombus) that adheres to the......
thrombosis
thrombosis, formation of a blood clot in the heart or in a blood vessel. Factors that play a role in the formation......
thrush
thrush, fungus infection characterized by raised white patches on the tongue. When gently scraped off, these patches......
thyroid tumour
thyroid tumour, any of various benign tumours (adenomas) or malignant tumours (cancers) of the thyroid gland. Thyroid......
thyroiditis
thyroiditis, any of many inflammatory diseases of the thyroid gland. Several nonspecific types of thyroiditis,......
tic
tic, (from the 17th-century French tic or ticq, “a twitching”), sudden rapid, recurring contraction in a muscle......
tinnitus
tinnitus, ringing or buzzing in the ears. An estimated one-third of adults experience tinnitus at some point in......
Today in History—July 27: When and Where the World’s First Quarantine Began
Every generation remembers its first plague: Ours is 2020 and COVID-19. But for the citizens of Ragusa—the Adriatic......
Today in History—June 24: The Outbreak of the Dancing Plague
On this day in 1374, the town of Aachen, Germany, went wild. Men, women, and children gathered in the streets.......
Today in History—March 24: The Lecture That Unraveled the Mystery of Tuberculosis
On this day in 1882, German physician Robert Koch gave a lecture at the monthly meeting of the Berlin Physiological......
Today in History—May 8: The End of Smallpox
On this day in 1980, the world reached a milestone few had ever thought possible: Smallpox was eradicated. This......
Today in History—September 19: Unraveling the Mystery of the Healthy Carrier
She showed no signs of illness. Yet everywhere Mary Mallon worked, typhoid fever seemed sure to follow. On September......
tongue-tie
tongue-tie, congenital shortening of the flap of mucous membrane (frenum) beneath the tongue, a condition that......
tonsillitis
tonsillitis, inflammatory infection of the tonsils caused by invasion of the mucous membrane by microorganisms,......
tooth squeeze
tooth squeeze, pain caused by the expansion or contraction of air beneath the filling of a tooth when pressure......
torticollis
torticollis, abnormality in which the neck is in a twisted, bent position such that the head is pulled to one side......
Tourette syndrome
Tourette syndrome, rare inherited neurological disorder characterized by recurrent motor and phonic tics (involuntary......
toxemia of pregnancy
toxemia of pregnancy, term formerly used to describe hypertensive conditions that can be induced by pregnancy.......
toxic shock syndrome
toxic shock syndrome, inflammatory disease characterized by high fever, headache, diarrhea, vomiting, irritability,......
toxin
toxin, any substance poisonous to an organism. The term is sometimes restricted to poisons spontaneously produced......
toxoplasmosis
toxoplasmosis, infection of cells of the central nervous system, spleen, liver, and other organs by a parasite,......
trachoma
trachoma, chronic inflammatory disease of the eye caused by Chlamydia trachomatis, a bacterium-like microorganism......
transduction
transduction, a process of genetic recombination in bacteria in which genes from a host cell (a bacterium) are......
traumatic brain injury
traumatic brain injury, any damage to the brain from an applied force. The forces involved can be from direct contact,......
trench fever
trench fever, infectious disease characterized by sudden onset of fever, headache, pain behind the eyes, weakness,......
trichinosis
trichinosis, disorder resulting from infestation with roundworms of genus Trichinella, especially the small roundworm......
trichomoniasis
trichomoniasis, infection by the flagellate protozoan parasite Trichomonas. Infection is most often intestinal,......
Trigger Warnings on Campus
In a 2015 letter to their student newspaper, four undergraduates at Columbia University called on the administration......
trisomy 13
trisomy 13, human chromosomal disorder that results from an extra (third) copy of chromosome 13. Trisomy 13 can......
trisomy 18
trisomy 18, human chromosomal disorder that results from an extra (third) copy of chromosome 18. Infants born with......
trisomy X
trisomy X, sex chromosome disorder of human females, in which three X chromosomes are present, rather than the......
tropical sprue
tropical sprue, rare acquired disease characterized by an impairment of the small intestine’s ability to absorb......
trypanosomiasis
trypanosomiasis, infectious disease in both humans and animals caused by certain members of the flagellate protozoa......
tuberculosis
tuberculosis (TB), infectious disease that is caused by the tubercle bacillus, Mycobacterium tuberculosis. In most......
tuberous sclerosis
tuberous sclerosis, autosomal dominant disorder marked by the formation of widespread benign tumors throughout......
tularemia
tularemia, acute infectious disease caused by the gram-negative bacterium Francisella tularensis known for its......
tumour
tumour, a mass of abnormal tissue that arises without obvious cause from preexisting body cells, has no purposeful......
turf toe
turf toe, sprain involving the big toe (hallux) metatarsophalangeal (MTP) joint of the foot. The term turf toe......
Turner syndrome
Turner syndrome, relatively uncommon sex-chromosome disorder that causes aberrant sexual development in human females.......
typhoid fever
typhoid fever, acute infectious disease caused by the bacterium Salmonella enterica serovar Typhi. The bacterium......
Typhoid Mary
Typhoid Mary was an infamous typhoid carrier who allegedly gave rise to multiple outbreaks of typhoid fever. Mary......
typhus
typhus, series of acute infectious diseases that appear with a sudden onset of headache, chills, fever, and general......
tyrosinemia
tyrosinemia, inherited inability of the body to metabolize normally the amino acid tyrosine. In the normal metabolic......
U.S. Death Toll During Major Events
This infographic shows the death toll caused by major events during the history of the United States, including......
ulcer
ulcer, a lesion or sore on the skin or mucous membrane resulting from the gradual disintegration of surface epithelial......
uremia
uremia, medical condition produced by the toxic effects of abnormally high concentrations of nitrogenous substances......
urethritis
urethritis, infection and inflammation of the urethra, the channel for passage of urine from the urinary bladder......
urinary tract infection
urinary tract infection (UTI), in humans, inflammation of the renal system characterized by frequent and painful......
urinary tract obstruction
urinary tract obstruction, blockage or constriction at any point in the urinary tract that impedes the normal flow......
urogenital malformation
urogenital malformation, any defect in the organs and tissues responsible for the formation and excretion of urine......
uterine bleeding
uterine bleeding, abnormal bleeding from the uterus, which is not related to menstruation. Menstruation is the......
uterine cancer
uterine cancer, a disease characterized by the abnormal growth of cells in the uterus. Endometrial cancer, which......
uterine fibroid
uterine fibroid, benign tumour that originates from the smooth muscle wall of the uterus and may be single but......
uveitis
uveitis, inflammation of the uvea (or uveal tract), the middle layer of tissue surrounding the eye that consists......
vaccine-associated feline sarcoma
vaccine-associated feline sarcoma, malignant tumour of cats that develops at the site of a vaccine injection. The......
vaginismus
vaginismus, involuntary muscle spasm that closes the opening to the vagina in the female reproductive tract. The......
vaginitis
vaginitis, inflammation of the vagina, usually due to infection. The chief symptom is the abnormal flow of a whitish......
Vanier, Jean
Jean Vanier was a Swiss-born Roman Catholic social activist, theologian, and philosopher who was involved in efforts......
varicose vein
varicose vein, vein that is twisted and distended with blood. The term varix is also used for similar abnormalities......
Venom
Venom, the poisonous secretion of an animal, produced by specialized glands that are often associated with spines,......
ventricular fibrillation
ventricular fibrillation, a type of arrhythmia (abnormal heart rhythm) characterized by the irregular and uncoordinated......
ventricular septal defect
ventricular septal defect, opening in the partition between the two ventricles, or lower chambers, of the heart.......
vertigo
vertigo, sensation of spinning or tilting or that one’s surroundings are rotating. Usually the state produces dizziness,......
vesicular exanthema of swine
vesicular exanthema of swine, viral disease of swine causing eruption of painful blisters on feet and snout. Blisters......
vesicular stomatitis
vesicular stomatitis, viral disease causing blisters in the mouths of cattle, horses, and mules and on the snouts......
vesiculitis
vesiculitis, inflammation and infection of the seminal vesicles in the male reproductive tract. The seminal vesicles......
Vincent gingivitis
Vincent gingivitis, acute and painful infection of the tooth margins and gums that is caused by the symbiotic microorganisms......
viral disease
viral disease, disease caused by viruses. Long-term immunity usually follows viral childhood diseases (see chickenpox).......
viral hemorrhagic fever
viral hemorrhagic fever, any of a variety of highly fatal viral diseases that are characterized by massive external......
Virchow, Rudolf
Rudolf Virchow was a German pathologist and statesman, one of the most prominent physicians of the 19th century.......
viroid
viroid, an infectious particle smaller than any of the known viruses, an agent of certain plant diseases. The particle......
visual field defect
visual field defect, a blind spot (scotoma) or blind area within the normal field of one or both eyes. In most......
vitamin A deficiency
vitamin A deficiency, nutritional disorder caused by a deficiency of vitamin A (also called retinol), a fat-soluble......
vitiligo
vitiligo, patchy loss of melanin pigment from the skin. Though the pigment-making cells of the skin, or melanocytes,......
Volkmann contracture
Volkmann contracture, disorder of the wrist and hand in which the hand and fingers become fixed in a characteristic......
vomiting
vomiting, the forcible ejection of stomach contents from the mouth. Like nausea, vomiting may have a wide range......
von Gierke’s disease
von Gierke’s disease, most common of a group of hereditary glycogen-storage diseases. It is inherited as an autosomal-recessive......
von Willebrand disease
von Willebrand disease, inherited blood disorder characterized by a prolonged bleeding time and a deficiency of......