Health Library A–Z

Acid reflux occurs when stomach acid flows back into the esophagus, causing a burning sensation in t...

Acne vulgaris is a common skin condition that occurs when hair follicles become clogged with oil and...

Addison's disease, also known as primary adrenal insufficiency, is a rare condition in which the adr...

Age-related macular degeneration (AMD) is a progressive eye disease that affects the macula — the ce...

Allergic rhinitis is an inflammatory condition of the nasal passages triggered by allergens such as ...

Alopecia is a broad term for hair loss that can affect the scalp or the entire body, ranging from mi...

Alzheimer's disease is a progressive neurodegenerative disorder and the most common cause of dementi...

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease that attacks the moto...

Anemia is a condition in which the blood lacks enough healthy red blood cells or hemoglobin to carry...

Angina is chest pain or discomfort caused by reduced blood flow to the heart muscle, typically due t...

Anxiety disorders are a group of mental health conditions characterized by excessive, persistent wor...

Appendicitis is an inflammation of the appendix, a small finger-shaped pouch attached to the large i...

Arthritis is a broad term for conditions that cause joint inflammation, pain, and stiffness, with os...

Asthma is a chronic respiratory condition in which the airways become inflamed, narrow, and produce ...

Atrial fibrillation (AFib) is the most common type of cardiac arrhythmia, characterized by rapid, ir...

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental condition characterized by p...

Back pain is one of the most common reasons people seek medical attention and miss work, affecting u...

Bell's palsy is a sudden, temporary weakness or paralysis of the muscles on one side of the face, ca...

Benign prostatic hyperplasia (BPH) is a non-cancerous enlargement of the prostate gland that commonl...

Bipolar disorder is a chronic mental health condition characterized by extreme mood swings that incl...

Bladder cancer is a common cancer that begins in the urothelial cells lining the inside of the bladd...

Blood clots are gel-like clumps of blood that form in veins or arteries, potentially blocking blood ...

Breast cancer is the most commonly diagnosed cancer in women worldwide, developing when cells in the...

Bronchitis is an inflammation of the bronchial tubes (bronchi) that carry air to and from the lungs....

Bulimia nervosa is a serious eating disorder characterized by recurring episodes of binge eating fol...

Burnout is a state of chronic physical and emotional exhaustion resulting from prolonged workplace s...

Bursitis is the inflammation of a bursa, a small fluid-filled sac that cushions bones, tendons, and ...

Cardiac arrhythmia refers to any irregularity in the heart's rhythm, including beating too fast (tac...

Carpal tunnel syndrome is a condition caused by compression of the median nerve as it passes through...

A cataract is a clouding of the eye's natural lens that lies behind the iris and pupil, causing visi...

Celiac disease is an autoimmune disorder in which the ingestion of gluten—a protein found in wheat, ...

Cellulitis is a common and potentially serious bacterial skin infection that affects the deeper laye...

Cervical cancer develops in the cells of the cervix, the lower part of the uterus that connects to t...

Chickenpox is a highly contagious viral infection caused by the varicella-zoster virus (VZV) that pr...

Chlamydia is the most commonly reported sexually transmitted infection (STI) in the United States, c...

Chronic fatigue syndrome (ME/CFS) is a complex, debilitating disorder characterized by extreme fatig...

Chronic kidney disease (CKD) is a progressive loss of kidney function over months or years, eventual...

Chronic obstructive pulmonary disease (COPD) is a group of progressive lung diseases—primarily emphy...

Chronic pain is pain that persists for more than three months, continuing beyond the normal healing ...

Cirrhosis is the late stage of progressive liver scarring (fibrosis) caused by long-term liver damag...

Cluster headaches are one of the most painful types of headache, characterized by severe, piercing p...

Cold sores are small, fluid-filled blisters that typically appear on or around the lips, caused by t...

Colic is a condition in otherwise healthy, well-fed infants characterized by frequent, prolonged, an...

Colorectal cancer is cancer that begins in the colon or rectum and is the third most common cancer d...

The common cold is a viral infection of the upper respiratory tract, primarily affecting the nose an...

A concussion is a mild traumatic brain injury caused by a blow, bump, or jolt to the head or body th...

Conjunctivitis, commonly known as pink eye, is an inflammation or infection of the transparent membr...

Conjunctivitis (pink eye) is an inflammation or infection of the transparent membrane (conjunctiva) ...

Coronary artery disease (CAD) is the most common type of heart disease and the leading cause of deat...

Costochondritis is an inflammation of the cartilage that connects a rib to the breastbone (sternum),...

Crohn's disease is a chronic inflammatory bowel disease (IBD) that can affect any part of the gastro...

Croup is a common childhood respiratory illness that causes swelling around the vocal cords and wind...

Cushing's syndrome is a hormonal disorder caused by prolonged exposure to high levels of the hormone...

Cystic fibrosis is a life-threatening inherited disorder that causes severe damage to the lungs, dig...

Deep vein thrombosis (DVT) occurs when a blood clot forms in a deep vein, usually in the legs. It is...

Dementia is an umbrella term for a group of symptoms affecting memory, thinking, and social abilitie...

Dengue fever is a mosquito-borne tropical disease caused by the dengue virus, transmitted primarily ...

Depression (major depressive disorder) is a common but serious mood disorder that causes persistent ...

Dermatitis is a general term for skin inflammation that causes itchy, red, swollen, and sometimes bl...

Diarrhea is characterized by loose, watery stools occurring three or more times per day, and is one ...

Diverticulitis occurs when small pouches (diverticula) that form in the walls of the colon become in...

Down syndrome is a genetic condition caused by the presence of an extra copy of chromosome 21 (triso...

Dry eye syndrome is a common condition that occurs when the eyes do not produce enough tears or when...

Dysmenorrhea refers to painful menstrual cramps that occur before or during menstruation and is the ...

An ear infection (otitis media) is an infection of the middle ear, the air-filled space behind the e...

Eating disorders are serious mental health conditions characterized by persistent disturbances in ea...

Eczema, also known as atopic dermatitis, is a chronic inflammatory skin condition that causes dry, i...

Edema is the medical term for swelling caused by excess fluid trapped in the body's tissues, most co...

Ehlers-Danlos syndrome (EDS) is a group of inherited connective tissue disorders caused by defects i...

Emphysema is a chronic, progressive lung disease and a major form of COPD in which the air sacs (alv...

Endocarditis is a serious infection of the inner lining of the heart chambers and valves, typically ...

Endometriosis is a chronic condition in which tissue similar to the uterine lining grows outside the...

Epilepsy is a chronic neurological disorder characterized by recurrent, unprovoked seizures caused b...

Erectile dysfunction (ED) is the persistent inability to achieve or maintain an erection firm enough...

Esophageal cancer develops in the lining of the esophagus, the tube that carries food from the throa...

Essential tremor is the most common movement disorder, causing involuntary rhythmic shaking most oft...

Eye floaters are small dark shapes that drift across your field of vision, appearing as spots, threa...

Fatty liver disease occurs when excess fat accumulates in liver cells, and is the most common liver ...

Fibrocystic breast changes are a common, noncancerous condition in which breasts develop lumpy, rope...

Fibromyalgia is a chronic pain condition characterized by widespread musculoskeletal pain, fatigue, ...

Folliculitis is a common skin condition in which hair follicles become inflamed, usually as a result...

Food poisoning is an illness caused by consuming contaminated food or beverages, most commonly from ...

Frozen shoulder is a condition characterized by stiffness, pain, and limited range of motion in the ...

Fungal nail infection, medically known as onychomycosis, is a common condition caused by dermatophyt...

Gallstones are hardened deposits of digestive fluid that form in the gallbladder. They range from gr...

A ganglion cyst is a noncancerous, fluid-filled lump that commonly develops along tendons or joints ...

Gastritis is the inflammation of the stomach lining, which can occur suddenly (acute) or develop gra...

Gastroenteritis is an inflammation of the stomach and intestines typically caused by viral or bacter...

GERD is a chronic condition in which stomach acid frequently flows back into the esophagus, irritati...

Gender dysphoria is the psychological distress from an incongruence between a person's gender identi...

Genital herpes is a common STI caused primarily by herpes simplex virus type 2 (HSV-2), though HSV-1...

Geographic tongue is a benign inflammatory condition causing irregular, smooth, red patches on the t...

Gestational diabetes is a form of high blood sugar that develops during pregnancy in women who did n...

Gingivitis is the earliest and mildest form of gum disease, characterized by inflammation, redness, ...

Glaucoma is a group of eye diseases that damage the optic nerve, usually due to abnormally high intr...

Gonorrhea is a sexually transmitted infection caused by the bacterium Neisseria gonorrhoeae. It can ...

Gout is a form of inflammatory arthritis caused by the buildup of uric acid crystals in the joints, ...

Graves' disease is an autoimmune disorder that causes the thyroid gland to produce excessive thyroid...

Guillain-Barré syndrome is a rare but serious autoimmune disorder in which the immune system attacks...

Hand, foot, and mouth disease (HFMD) is a common, highly contagious viral illness primarily affectin...

Hashimoto's thyroiditis is an autoimmune disorder in which the immune system attacks the thyroid gla...

Head lice are tiny parasitic insects (Pediculus humanus capitis) that infest the hair and scalp, fee...

Hearing loss is a partial or total inability to hear sounds in one or both ears, ranging from mild d...

A heart attack occurs when blood flow to a section of the heart muscle is blocked, usually by a bloo...

Heart failure is a chronic, progressive condition in which the heart cannot pump blood efficiently e...

Heart palpitations are sensations of a pounding, fluttering, racing, or skipping heartbeat that can ...

Heat stroke is a life-threatening condition in which the body's core temperature rises above 104°F (...

Hemophilia is a rare inherited bleeding disorder in which the blood does not clot properly due to a ...

Hemorrhoids are swollen veins in the lower rectum and anus that can develop internally or externally...

Hepatic encephalopathy is a decline in brain function occurring when the liver cannot adequately rem...

Hepatitis A is a highly contagious liver infection caused by the hepatitis A virus, typically spread...

Hepatitis B is a viral liver infection transmitted through blood, semen, and other body fluids. Whil...

Hepatitis C is a viral liver infection primarily spread through contact with infected blood. Chronic...

A hernia occurs when an organ or tissue pushes through a weak spot in the surrounding muscle or conn...

A herniated disc occurs when the soft, gel-like center (nucleus pulposus) of a spinal disc pushes th...

Herpes simplex virus infections are caused by HSV-1 (primarily oral herpes) and HSV-2 (primarily gen...

Hidradenitis suppurativa (HS) is a chronic, inflammatory skin condition characterized by painful lum...

High blood pressure is a chronic condition in which the force of blood against artery walls is consi...

High cholesterol is a condition in which there is an excess of cholesterol in the blood, particularl...

HIV attacks the immune system's CD4+ T cells, and if untreated, leads to AIDS. Modern antiretroviral...

Hives are raised, itchy welts on the skin that appear suddenly, caused by the release of histamine f...

HPV is the most common STI, with over 200 types identified. Most infections are harmless and clear o...

Huntington's disease is a progressive, inherited neurodegenerative disorder caused by a mutation in ...

Hyperthyroidism is a condition in which the thyroid gland produces too much thyroid hormone, acceler...

Hypoglycemia occurs when blood glucose levels drop below 70 mg/dL, causing a range of symptoms from ...

Hypothyroidism occurs when the thyroid gland does not produce enough thyroid hormone, slowing metabo...

ITP is an autoimmune disorder in which the immune system destroys platelets, the blood cells respons...

Impetigo is a highly contagious superficial bacterial skin infection most common in young children, ...

Infertility is defined as the inability to conceive after 12 months of regular unprotected intercour...

Influenza is a contagious respiratory illness caused by influenza viruses that infect the nose, thro...

An ingrown toenail occurs when the edge or corner of a toenail grows into the surrounding skin, caus...

Insomnia is a common sleep disorder characterized by difficulty falling asleep, staying asleep, or w...

Interstitial cystitis is a chronic condition causing bladder pressure, pain, and sometimes pelvic pa...

Iron deficiency anemia is the most common type of anemia worldwide, occurring when the body lacks su...

IBS is a common functional gastrointestinal disorder characterized by chronic abdominal pain and alt...

Jaundice is yellowing of the skin and eyes caused by elevated bilirubin in the blood. It is not a di...

Keloids are raised, overgrown scars that develop when the body produces excessive collagen during th...

Kidney cancer, most commonly renal cell carcinoma, originates in the kidney tubule lining and is oft...

Kidney stones are hard mineral and salt deposits that form inside the kidneys when urine becomes con...

Kidney stones are hard deposits made of minerals and salts that form inside the kidneys when urine b...

Knee pain is one of the most common musculoskeletal complaints affecting all ages and activity level...

Lactose intolerance is a common digestive condition in which the body cannot fully digest lactose, t...

Laryngitis is inflammation of the voice box (larynx) caused by overuse, irritation, or infection, re...

Leukemia is a group of cancers that begin in blood-forming cells of the bone marrow, leading to over...

Lichen planus is a chronic inflammatory condition affecting the skin, mucous membranes, hair, and na...

A lipoma is a slow-growing, benign (non-cancerous) tumor made up of fat cells that forms between the...

Liver cancer, most commonly hepatocellular carcinoma, typically develops in livers already damaged b...

Long COVID refers to new, returning, or ongoing health problems persisting four or more weeks after ...

Low back pain is one of the most common reasons for medical visits and the leading cause of disabili...

Lung cancer is the leading cause of cancer death worldwide, most commonly caused by smoking but also...

Lupus is a chronic autoimmune disease in which the immune system attacks the body's own tissues, pot...

Lyme disease is the most common tick-borne illness in North America and Europe, caused by Borrelia b...

Lymphoma is a cancer of the lymphatic system. The two main types are Hodgkin lymphoma (with Reed-Ste...

Malaria is a life-threatening mosquito-borne disease caused by Plasmodium parasites transmitted thro...

Measles is a highly contagious viral infection caused by the measles virus, spread through respirato...

Melanoma is the most serious type of skin cancer, developing from the pigment-producing cells known ...

Meniere's disease is a chronic inner ear disorder characterized by recurring episodes of vertigo, fl...

Meningitis is an inflammation of the protective membranes (meninges) surrounding the brain and spina...

Menopause is a natural biological process marking the permanent end of menstrual periods, diagnosed ...

Mesothelioma is an aggressive and often fatal cancer that develops in the mesothelium, the thin laye...

Migraine is a complex neurological condition characterized by intense, throbbing headaches that can ...

A miscarriage is the spontaneous loss of a pregnancy before the 20th week of gestation, with most oc...

Infectious mononucleosis is a common viral illness most often caused by the Epstein-Barr virus (EBV)...

MRSA is a type of Staphylococcus aureus bacteria that has developed resistance to methicillin and ma...

Multiple myeloma is a cancer of plasma cells — white blood cells that produce antibodies — in the bo...

Multiple sclerosis (MS) is a chronic autoimmune disease in which the immune system attacks the prote...

Mumps is a contagious viral infection caused by the mumps virus, a paramyxovirus spread through sali...

Muscle cramps are sudden, involuntary contractions of one or more muscles that can cause intense pai...

Myasthenia gravis is a chronic autoimmune neuromuscular disorder in which antibodies block or destro...

Myocarditis is an inflammation of the heart muscle (myocardium), most commonly caused by viral infec...

Narcolepsy is a chronic neurological disorder that impairs the brain's ability to regulate sleep-wak...

Nausea is an uncomfortable sensation of unease in the stomach that often precedes vomiting, and it i...

Neck pain is an extremely common condition affecting the cervical spine and surrounding muscles, lig...

Non-Hodgkin lymphoma (NHL) is a diverse group of blood cancers that develop in the lymphatic system,...

Norovirus is a highly contagious virus that causes acute gastroenteritis, leading to sudden onset of...

A nosebleed (epistaxis) is bleeding from the blood vessels inside the nose, most commonly from the a...

Obesity is a complex, chronic medical condition characterized by excessive body fat accumulation tha...

Obsessive-compulsive disorder (OCD) is a chronic mental health condition characterized by recurring,...

Oral cancer encompasses cancers of the lips, tongue, floor of the mouth, cheeks, gums, hard and soft...

Oral thrush is a fungal infection of the mouth caused by an overgrowth of Candida species, most comm...

Osteoarthritis is the most common form of arthritis, caused by the progressive breakdown of cartilag...

Osteoporosis is a systemic skeletal disorder characterized by decreased bone density and deteriorati...

Otitis media is an infection or inflammation of the middle ear, most common in children between 6 mo...

Ovarian cancer is a group of cancers originating in or near the ovaries, fallopian tubes, or periton...

Overactive bladder (OAB) is a condition characterized by a sudden, uncontrollable urge to urinate, o...

Pancreatic cancer is one of the most aggressive and lethal cancers, arising primarily from the exocr...

Pancreatitis is inflammation of the pancreas that can occur as an acute episode or as a chronic, pro...

Panic disorder is an anxiety disorder characterized by recurrent, unexpected panic attacks — sudden ...

Parkinson's disease is a progressive neurodegenerative disorder resulting from the loss of dopamine-...

Pelvic inflammatory disease (PID) is an infection of the female upper reproductive tract, including ...

Peptic ulcer disease involves open sores that develop on the inner lining of the stomach (gastric ul...

Pericarditis is inflammation of the pericardium, the thin two-layered sac surrounding the heart, cau...

Peripheral artery disease (PAD) is a circulatory condition in which narrowed arteries, usually due t...

Peripheral neuropathy refers to damage or dysfunction of the peripheral nerves, causing weakness, nu...

Pertussis (whooping cough) is a highly contagious respiratory infection caused by the bacterium Bord...

Pharyngitis is inflammation of the pharynx (back of the throat), resulting in a sore throat that is ...

A pilonidal cyst is a pocket that forms in the skin at the top of the crease between the buttocks (n...

A pinched nerve occurs when excessive pressure is applied to a nerve by surrounding tissues such as ...

Plantar fasciitis is the most common cause of heel pain, resulting from inflammation and degeneratio...

Pleurisy is an inflammation of the pleura — the two-layered membrane surrounding the lungs and linin...

Pneumonia is an infection of the lungs that inflames the air sacs (alveoli), causing them to fill wi...

Poison ivy rash is an allergic contact dermatitis caused by urushiol, an oily resin found in the lea...

Polycystic kidney disease (PKD) is an inherited disorder in which clusters of fluid-filled cysts dev...

Polycystic ovary syndrome (PCOS) is a common hormonal disorder affecting women of reproductive age, ...

Post-traumatic stress disorder (PTSD) is a mental health condition triggered by experiencing or witn...

Postpartum depression is a serious mood disorder that can develop after childbirth, typically within...

Preeclampsia is a serious pregnancy complication characterized by high blood pressure and signs of o...

Premenstrual syndrome (PMS) encompasses a wide range of physical, emotional, and behavioral symptoms...

Pressure ulcers, commonly known as bedsores or decubitus ulcers, are injuries to the skin and underl...

Prostate cancer is the most common cancer in men (excluding skin cancer) and develops in the prostat...

Prostatitis is inflammation of the prostate gland that can cause pain, difficulty urinating, and sex...

Psoriasis is a chronic autoimmune skin condition that speeds up the life cycle of skin cells, causin...

A pulmonary embolism (PE) occurs when a blood clot, usually originating from the deep veins of the l...

Pulmonary fibrosis is a chronic, progressive lung disease in which the tissue deep in the lungs beco...

Raynaud's disease is a condition in which smaller arteries that supply blood to the skin constrict e...

Respiratory syncytial virus (RSV) is a highly contagious virus that infects the lungs and breathing ...

Restless legs syndrome (RLS) is a neurological sensorimotor disorder characterized by an irresistibl...

Rheumatoid arthritis (RA) is a chronic autoimmune disorder that primarily attacks the synovial linin...

Ringworm is a common fungal skin infection caused by dermatophytes — not an actual worm. It appears ...

Rosacea is a chronic inflammatory skin condition primarily affecting the central face, characterized...

A rotator cuff injury involves damage to the group of four muscles and tendons that stabilize the sh...

Rotavirus is a highly contagious virus that is the leading cause of severe diarrhea in infants and y...

Sarcoidosis is an inflammatory disease characterized by the formation of tiny clumps of inflammatory...

Scabies is a highly contagious skin infestation caused by the microscopic mite Sarcoptes scabiei, wh...

Scarlet fever is a bacterial illness caused by group A Streptococcus that produces a toxin leading t...

Schizophrenia is a chronic and severe mental health disorder that affects how a person thinks, feels...

Sciatica refers to pain that radiates along the path of the sciatic nerve, which runs from the lower...

Scleroderma is a group of rare autoimmune diseases that cause hardening and tightening of the skin a...

Scoliosis is a sideways curvature of the spine that most often develops during the growth spurt just...

Seasonal affective disorder is a type of depression that follows a seasonal pattern, most commonly o...

Seborrheic dermatitis is a common, chronic skin condition that causes red, scaly, and itchy patches ...

Sepsis is a life-threatening medical emergency that occurs when the body's response to an infection ...

Sexually transmitted infections are infections spread primarily through sexual contact including vag...

Shin splints, medically known as medial tibial stress syndrome, is a common exercise-related conditi...

Shingles is a viral infection caused by the reactivation of the varicella-zoster virus, the same vir...

Sickle cell disease is a group of inherited blood disorders in which red blood cells become misshape...

Sinusitis is an inflammation or swelling of the tissue lining the sinuses, the air-filled cavities i...

Sjögren's syndrome is a chronic autoimmune disorder in which the immune system attacks the glands th...

Skin cancer is the abnormal growth of skin cells, most commonly caused by excessive ultraviolet radi...

Sleep apnea is a serious sleep disorder in which breathing repeatedly stops and starts during sleep....

Sleep disorders are conditions that impair the ability to get adequate, restful sleep on a regular b...

Small intestinal bacterial overgrowth (SIBO) is a condition in which excessive amounts of bacteria c...

Smallpox was a highly contagious and deadly viral disease caused by the variola virus, characterized...

Snoring is the hoarse or harsh sound that occurs when air flows past relaxed tissues in the throat, ...

Social anxiety disorder is a chronic mental health condition characterized by an intense, persistent...

Spider veins are small, damaged veins that appear on the surface of the skin as thin red, blue, or p...

Spinal stenosis is a narrowing of the spaces within the spine that puts pressure on the spinal cord ...

Sprains and strains are among the most common musculoskeletal injuries, involving damage to ligament...

Staphylococcal infections are caused by Staphylococcus bacteria, commonly found on the skin and in t...

Stomach cancer, also known as gastric cancer, develops from the lining of the stomach and often grow...

Stomach ulcers are open sores that develop on the inner lining of the stomach, often causing a burni...

Strep throat is a bacterial infection of the throat and tonsils caused by group A Streptococcus bact...

Stress urinary incontinence is the involuntary leakage of urine during activities that increase abdo...

A stroke occurs when blood flow to a part of the brain is interrupted or severely reduced, depriving...

A stye is a painful, red bump that forms on the edge of the eyelid, caused by a bacterial infection ...

Substance use disorder is a chronic brain condition characterized by the compulsive use of substance...

Sunburn is skin damage caused by overexposure to ultraviolet radiation from the sun or artificial so...

Swimmer's ear, medically known as otitis externa, is an infection of the outer ear canal that runs f...

Swollen lymph nodes, or lymphadenopathy, occur when lymph nodes enlarge in response to infection, in...

Syphilis is a sexually transmitted bacterial infection caused by Treponema pallidum that progresses ...

Systemic lupus erythematosus is a chronic autoimmune disease in which the immune system attacks the ...

Tardive dyskinesia is a movement disorder characterized by involuntary, repetitive facial and body m...

Temporomandibular joint disorder encompasses a group of conditions affecting the jaw joint and the m...

Tendinitis is the inflammation or irritation of a tendon, the thick fibrous cord that attaches muscl...

Tennis elbow, or lateral epicondylitis, is a painful condition caused by overuse of the forearm musc...

Tension headaches are the most common type of headache, producing a dull, aching pain that typically...

Testicular cancer develops in one or both testicles and is the most common cancer in young men aged ...

Tetanus is a serious bacterial infection caused by Clostridium tetani that produces a toxin affectin...

Thalassemia is an inherited blood disorder in which the body produces abnormal or insufficient amoun...

Thoracic outlet syndrome is a group of disorders that occur when blood vessels or nerves in the thor...

Thyroid cancer develops in the thyroid gland, a butterfly-shaped gland at the base of the neck that ...

Thyroid nodules are growths or lumps within the thyroid gland that are very common, particularly in ...

Tinnitus is the perception of ringing, buzzing, hissing, or other sounds in the ears when no externa...

Tonsillitis is an inflammation of the tonsils, the two oval-shaped pads of tissue at the back of the...

A tooth abscess is a pocket of pus caused by a bacterial infection that can occur at different areas...

A torn ACL (anterior cruciate ligament) is one of the most common knee injuries, frequently occurrin...

Tourette syndrome is a neurological disorder characterized by repetitive, involuntary movements and ...

Toxic shock syndrome (TSS) is a rare but life-threatening condition caused by toxins produced by cer...

A transient ischemic attack is a temporary episode of neurological symptoms caused by a brief interr...

Traumatic brain injury occurs when an external force causes damage to the brain, ranging from mild c...

Trichomoniasis is a common sexually transmitted infection caused by the parasite Trichomonas vaginal...

Trigeminal neuralgia is a chronic pain condition affecting the trigeminal nerve, which carries sensa...

Trigger finger is a condition in which a finger or thumb gets stuck in a bent position and then snap...

Tuberculosis is a potentially serious infectious disease primarily affecting the lungs, caused by th...

Turner syndrome is a chromosomal condition that affects only females, occurring when one of the X ch...

Type 1 diabetes is a chronic autoimmune condition in which the immune system attacks and destroys th...

Type 2 diabetes is a chronic metabolic condition characterized by insulin resistance and relative in...

Ulcerative colitis is a chronic inflammatory bowel disease that causes long-lasting inflammation and...

A urinary tract infection is an infection in any part of the urinary system, including the kidneys, ...

Uterine fibroids are noncancerous growths of the uterus that develop from smooth muscle tissue. They...

Uterine fibroids are noncancerous growths of the uterus that often appear during childbearing years....

Uveitis is inflammation of the uvea, the middle layer of the eye that includes the iris, ciliary bod...

A vaginal yeast infection is a fungal infection caused by an overgrowth of Candida species—most comm...

Vaginitis is inflammation of the vagina that can result in discharge, itching, and pain. The most co...

Varicose veins are enlarged, twisted veins that most commonly appear in the legs and feet, resulting...

Vasculitis is a group of disorders characterized by inflammation of the blood vessels, which can cau...

Vertigo is a sensation of spinning or whirling even when you are stationary, often caused by problem...

Vitamin B12 deficiency occurs when the body lacks adequate cobalamin, a vitamin essential for red bl...

Vitamin D deficiency occurs when the body does not get or produce enough vitamin D, a fat-soluble vi...

Vitiligo is a chronic skin condition in which the cells that produce melanin (melanocytes) are destr...

Vulvodynia is chronic pain or discomfort in the vulvar area lasting at least three months without an...

Warts are benign skin growths caused by the human papillomavirus (HPV) that infects the top layer of...

West Nile virus is a mosquito-borne flavivirus that can cause a range of illness from mild fever to ...

Whiplash is a neck injury caused by a sudden, forceful back-and-forth movement of the head, most com...

Whooping cough is a highly contagious respiratory infection caused by the bacterium Bordetella pertu...

Wilson's disease is a rare inherited disorder in which excess copper accumulates in the liver, brain...

Yellow fever is a serious viral hemorrhagic disease transmitted by infected mosquitoes, primarily in...

Zika virus is a mosquito-borne flavivirus primarily spread by Aedes mosquitoes that gained global at...