Abdominal migraine in children facts Abdominal migraine is believed to be a variant of migraine that is common in children but rare in adults. Abdominal migraine is characterized by pain in the center of the abdomen that m...

Abdominal migraine in children facts Abdominal migraine is believed to be a variant of migraine that is common in children but rare in adults. Abdominal migraine is characterized by pain in the center of the abdomen that m...

Primary aldosteronism (al-DOS-tuh-ro-niz-um) is a type of hormonal disorder that leads to high blood pressure. Your adrenal glands produce a number of essential hormones. One of these is aldosterone, which balances sodium and potassium in your blo...

What is angina? The heart is the pump responsible for circulating blood throughout the body. Myocardium (myo=muscle + cardium=muscle) is the heart muscle that contracts to pump that blood and like any other muscle, it requires oxygen rich ...

The heart is the pump responsible for circulating blood throughout the body. Myocardium (myo=muscle + cardium=muscle) is the heart muscle that contracts to pump that blood and like any other muscle, it requires oxygen rich blood for energy. Angina...

Introduction to aortic dissection The aorta is the large blood vessel that leads from the heart and carries blood to the rest of the body. It originates at the aortic valve at the outlet of the left ventricle of the heart and ascends withi...

The appendix is a small, worm-like appendage attached to the colon. Appendicitis occurs when bacteria invade and infect the wall of the appendix. The most common complications of appendicitis are rupture, abscess, and peritonitis....

The botulism neurotoxin is one of the most potent, lethal substances known. Botulism is a disease caused by this neurotoxin (specifically A, B, E, or F type neurotoxin). The neurotoxin is produced by bacteria called Clostr...

Brain aneurysm  An aneurysm is a ballooning at a weak spot in an artery wall. An aneurysm's walls can be thin enough to rupture. The illustration shows an individual with an unruptured aneurysm. The inset shows what happens when the a...

What is brain cancer? Brain cancer is a disease of the brain in which cancer cells (malignant cells) arise in the brain tissue. Cancer cells grow to form a mass of cancer tissue (tumor) that interferes with brain functions such as muscle c...

A brain tumor is a mass or growth of abnormal cells in your brain. Many different types of brain tumors exist. Some brain tumors are noncancerous (benign), and some brain tumors are cancerous (malignant). Brain tumors can begin in your bra...

A brain tumor is a mass or growth of abnormal cells in your brain. Many different types of brain tumors exist. Some brain tumors are noncancerous (benign), and some brain tumors are cancerous (malignant). Brain tumors can begin in your bra...

A brain tumor is a mass or growth of abnormal cells in your brain. Many different types of brain tumors exist. Some brain tumors are noncancerous (benign), and some brain tumors are cancerous (malignant). Brain tumors can begin in your bra...

Dengue Fever is an acute viral infection characterized by fever. It is caused by a bite from mosquitoes carrying dengue virus. The primary form of Dengue Fever is characterized by a skin rash and a high fever with severe pain in the head and muscl...

Familial articular chondrocalcinosis is a rare inherited metabolic disorder characterized by deposits of calcium pyrophosphate dihydrate crystals (CPPD) in one or more joint cartilages resulting in eventual damage to the joints. Symptoms may devel...

Campylobacteriosis is an infection caused by bacteria y...

Campylobacteriosis is a bacterial infection caused by Campylobacter bacteria. It is one of the most common causes of foodborne illness in the world, typically contracted through the consumption of contaminated food or water. Symptoms of campylobac...

Celiac disease, sometimes called celiac sprue or gluten-sensitive enteropathy, i...

Budd-Chiari syndrome is a rare disorder characterized by narrowing and obstruction (occlusion) of the veins of the liver (hepatic veins). Symptoms associated with Budd Chiari syndrome include pain in the upper right part of the abdomen, an abnorma...

Cyclic vomiting syndrome (CVS) is a rare disorder characterized by recurrent, similar episodes of severe nausea and vomiting. An episode may last for a few hours to several days and then is followed by a period of time during which affected indivi...

Collagenous colitis is a rare digestive disorder that primarily affects females and typically becomes apparent during middle age. The disorder is characterized by inflammatory changes of the mucous membranes (mucosa) of the colon (colitis) and abn...

Ulcerative colitis (UL-sur-uh-tiv koe-LIE-tis) is an inflammatory bowel disease ...

Ulcerative colitis (UL-sur-uh-tiv koe-LIE-tis) is an inflammatory bowel disease (IBD) that causes inflammation and ulcers (sores) in your digestive tract. Ulcerative colitis affects the innermost lining of your large intestine (colon) and rectum. ...

Crohn's disease facts Crohn's disease is a chronic inflammatory disease of the intestines. The cause of Crohn's disease is unknown. Crohn's disease can cause ulcers in the small intestine, colon, or both. ...

Cryptosporidiosis is a diarrheal disease caused by microscopic parasites, Cryptosporidium, that can live in the intestine of humans and animals and is passed in the stool of an infected person or animal. Both the disease and the parasite are commo...

Cryptosporidiosis is a parasitic infection caused by the Cryptosporidium parasite. It is typically transmitted through contaminated water or food, or through contact with infected animals or people. Symptoms of cryptosporidiosis include diarrhea, ...

  Cyclic vomiting syndrome is a disorder that causes recurrent episodes of nausea, vomiting, and tiredness (lethargy) most often in children but may occur in all age groups. Symptoms of cyclic vomiting syndrome are re...

Cyclic vomiting syndrome is characterized by episodes of severe vomiting that ha...

Autosomal dominant interstitial kidney disease describes a group of diseases affecting solely the proper function of the kidney and having the following characteristics: They are inherited in an autosomal dominant manner; kidney disease develops, ...

Autosomal dominant interstitial kidney disease describes a group of diseases affecting solely the proper function of the kidney and having the following characteristics: They are inherited in an autosomal dominant manner; kidney disease develops, ...

General DiscussionCytochrome C Oxidase deficiency is a very rare inherited metabolic disorder characterized by deficiency of the enzyme cytochrome C oxidase (COX), or Complex IV, an essential enzyme that is active in the subcellular struc...

Diabetic ketoacidosis is a serious complication of diabetes that occurs when you...

Diabetic ketoacidosis is a serious complication of diabetes that occurs when you...

Escherichia coli (E. coli) bacteria normally live in the intestines of healthy people and animals. Most varieties of E. coli are harmless or cause relatively brief diarrhea. But a few particularly nasty strains, such as E. coli O157:H7, can cause ...

E. coli infection is a type of bacterial infection caused by the bacterium Escherichia coli. E. coli bacteria are commonly found in the intestines of humans and animals, and most strains are harmless. However, some strains of E. coli can cause ill...

An ectopic pregnancy is a pregnancy located outside the inner lining of the uterus. Risk factors for ectopic pregnancy include previous ectopic pregnancies and conditions (surgery, infection) that disrupt the normal anatomy of the F...

Japanese Encephalitis is a severe inflammation of the brain caused by the Japanese B Encephalitis Virus that is transmitted by the bite of infected mosquitoes in certain areas of the world, particularly Asia. This disorder most commonly affects ch...

Enterovirulent E. coli (EEC) facts Enterovirulent E. coli (EEC) are bacteria that comprise several groups of E. coli serovars, all of which may cause diarrhea and other problems in the intestines. EEC bacteria can cause a ...

The largest part of the brain, the cerebrum, is divided into four paired sections -- the frontal, parietal, occipital, and temporal lobes. Each lobe controls a specific group of activities. The temporal lobe, located on either side of the brain ju...

The largest part of the brain, the cerebrum, is divided into four paired sections -- the frontal, parietal, occipital, and temporal lobes. Each lobe controls a specific group of activities. The temporal lobe, located on either side of the brain ju...

General DiscussionCongenital rubella is a syndrome that occurs when a fetus has been infected with the rubella virus while in the uterus. It is primarily characterized by abnormalities of the heart and nervous system, the eyes and the ear...

Fitz-Hugh-Curtis syndrome is a rare disorder that occurs almost exclusively in women. It is characterized by inflammation of the membrane lining the stomach (peritoneum) and the tissues surrounding the liver (perihepatitis). The muscle that separa...

Chiari-Frommel Syndrome is a rare endocrine disorder that affects women who have recently given birth (postpartum) and is characterized by the over-production of breast milk (galactorrhea), lack of ovulation (anovulation), and the absence of regul...

Gastritis is inflammation of the lining of the stomach. Unfortunately, the term "gastritis" has been misused to include many different upper abdominal problems, but true gastritis refers to the stomach lining (gastric mucosa) that is inflamed. All...

Definition of gastroenteritis Gastroenteritis (often referred to as the "stomach flu," however, it is not related to the influenza virus. Gastroenteritis is a nonspecific term for various inflammatory problems in the gastrointestinal tract...

Giardiasis is a common intestinal infection caused by a microscopic parasite called Giardia lamblia. It is typically contracted by ingesting contaminated food or water, and can cause symptoms such as diarrhea, abdominal cramps, bloating, and weigh...

Glaucoma is a disease that is often associated with elevated intraocular pressure, in which damage to the eye (optic) nerve can lead to loss of vision and even blindness. Glaucoma is the leading cause of irreversible blindness in th...

Glucose-galactose malabsorption is an inherited metabolic disorder characterized by the small intestine's inability to transport and absorb glucose and galactose (simple sugars or monosaccharides). Glucose and galactose have very similar chemical ...

Glutaricaciduria II is one of the conditions termed organic acidemias. Individuals with these conditions have a deficiency or absence of an enzyme that prevents them from breaking down certain chenicals in the body, resulting the accumulation of s...

Vogt-Koyanagi-Harada disease is a rare disorder of unknown origin that affects many body systems, including as the eyes, ears, skin, and the covering of the brain and spinal cord (the meninges). The most noticeable symptom is a rapid loss of visio...

What Is Restrictive Cardiomyopathy? Restrictive cardiomyopathy, the rarest form of cardiomyopathy, is a condition in which the walls of the lower chambers of the heart (the ventricles) are abnormally rigid and lack the flexibility to expan...

Introduction to heart transplant The idea of replacing a bad organ with a good one has been documented in ancient mythology. The first real organ transplants were probably skin grafts that may have been done in India as early as the second...

Helicobacter pylori (H. pylori) facts Helicobacter pylori (H. pylori) is a bacterium that causes chronic inflammation in the stomach and is a common cause of ulcers worldwide H. pylori causes chronic inflammation (gastriti...

Hemolytic uremic syndrome (HUS) is a condition caused by the abnormal destruction of red blood cells. The damaged red blood cells clog the filtering system in the kidneys, which can lead to life-threatening kidney failure. HUS usually deve...

Hepatitis A is a highly contagious liver infection caused by the hepatitis A virus. It is typically spread through contaminated food or water, or through close contact with an infected person. Symptoms of hepatitis A can include fever, fatigue, lo...

Hepatitis B is a viral infection that attacks the liver and can cause both acute and chronic disease. The virus is transmitted through contact with the blood or other body fluids of an infected person. Hepatitis B can be a mild illness lasting a f...

Hepatitis C is a viral infection that causes liver inflammation, sometimes leading to serious liver damage. The hepatitis C virus (HCV) is spread through contact with infected blood, most commonly through sharing needles or other equipment used to...

Hepatitis D, also known as delta hepatitis, is a liver infection caused by the hepatitis D virus (HDV). HDV is a small, defective RNA virus that can only replicate in the presence of the hepatitis B virus (HBV). This means that a person can only g...

Hepatitis E is a liver infection caused by the hepatitis E virus (HEV). It is typically a self-limiting illness that resolves on its own within a few weeks. However, in some cases, it can cause acute liver failure, especially in pregnant women and...

The esophagus connects the mouth and throat to the stomach. It passes through the chest cavity and enters the abdominal cavity through a hole in the diaphragm called the esophageal hiatus. The term hiatal hernia describes a condition where a part ...

Kikuchi's disease, also known as histiocytic necrotizing lymphadenopathy, is a rare, benign, (noncancerous, nonmalignant) disorder of the lymph nodes of young adults, predominantly in young women. This disorder is often mistaken for malignant lymp...

Papular urticaria, usually called hives, is characterized by large numbers of very itchy red bumps (papules) that come and go every few days over a period of a month or so. The bumps are usually between 0.2 and 2 cm. in size and some may develop i...

Bartter's syndrome (BS) is a group of conditions involving enlargement of certain kidney cells, blood that is more alkaline than normal, high levels of potassium and chloride in the urine, loss of potassium from the kidneys (renal potassium wastin...

Williams syndrome, also known as Williams-Beuren syndrome, is a rare genetic disorder characterized by growth delays before and after birth (prenatal and postnatal growth retardation), short stature, a varying degree of mental deficiency, and dist...

High blood sugar (hyperglycemia) affects people who have diabetes. Several facto...

Dyspepsia (indigestion) facts Dyspepsia is a functional disease in which the gastrointestinal organs, primarily the stomach and first part of the small intestine, function abnormally. It is a chronic disease in which the symptoms fl...

Kenny-Caffey syndrome type 2 (KCS2) is an extremely rare hereditary skeletal disorder characterized by thickening of the long bones, thin marrow cavities in the bones (medullary stenosis), and abnormalities affecting the head and eyes. Most cases ...

Kenny-Caffey syndrome type 2 (KCS2) is an extremely rare hereditary skeletal disorder characterized by thickening of the long bones, thin marrow cavities in the bones (medullary stenosis), and abnormalities affecting the head and eyes. Most cases ...

The Course of Kidney Disease Diabetic kidney disease takes many years to develop. In some people, the filtering function of the kidneys is actually higher than normal in the first few years of their diabetes. Over several years, pe...

Kikuchi's disease, also known as histiocytic necrotizing lymphadenopathy, is a rare, benign, (noncancerous, nonmalignant) disorder of the lymph nodes of young adults, predominantly in young women. This disorder is often mistaken for malignant lymp...

Degos disease is an extremely rare disorder in which small and medium sized arteries become blocked (occlusive arteriopathy), restricting the flow of blood to affected areas. Degos disease usually causes characteristic skin lesions that may last f...

Madelung's disease is a disorder of fat metabolism (lipid storage) that results in an unusual accumulation of fat deposits around the neck and shoulder areas. Adult alcoholic males are most often affected, although women and those who do not drink...

Von Hippel-Lindau syndrome (VHL) is an autosomal dominant genetic disorder characterized by the abnormal growth of blood vessels in certain parts of the body (angiomatosis). Very small blood vessels (capillaries) "knot" together to form benign gro...

Listeriosis is a serious infection usually caused by eating food contaminated with the bacterium Listeria monocytogenes. It primarily affects pregnant women, newborns, the elderly, and individuals with weakened immune systems. Symptoms may include...

Listeriosis is an infection caused by a gram-positive motile bacterium named Listeria monocytogenes. The infection produces fever, muscle aches, and, in many people, diarrhea. Severe infections can cause headaches, meningitis, convulsions, and dea...

Drug-induced liver diseases are diseases of the liver that are caused by physician-prescribed medications, over-the-counter medications, vitamins, hormones, herbs, illicit ("recreational") drugs, and environmental toxins. What is the liver...

Urticaria pigmentosa is a rare skin disorder that is a localized (cutaneous) form of mastocytosis. Some clinicians suggest that urticaria pigmentosa is the childhood form of mastocytosis. Mast cells are specialized cells of connective tissue that ...

Mallory-Weiss syndrome refers to a tear or laceration of the mucous membrane, most commonly at the point where the esophagus and the stomach meet (gastroesophageal junction). Such a tear may result in severe bleeding from the gastrointestinal trac...

Mallory-Weiss syndrome refers to a tear or laceration of the mucous membrane, most commonly at the point where the esophagus and the stomach meet (gastroesophageal junction). Such a tear may result in severe bleeding from the gastrointestinal trac...

Encephalitis is an inflammation of the brain. Meningitis is an inflammation of the membranes (called meninges) that surround the brain and spinal cord. Both infections can be caused by bacteria or viruses and rarely a fung...

Meningococcal disease is a serious bacterial infection caused by the bacterium Neisseria meningitidis. It can lead to meningitis (inflammation of the membranes surrounding the brain and spinal cord) and septicemia (blood poisoning). Meningococcal ...

Menstrual cramps that occur in the absence of a known abnormality or cause are medically referred to as primary dysmenorrhea. Non-drug treatments for menstrual cramps include adequate rest and sleep, regular exercise (especially wal...

Migraine headache is a result of specific changes within the brain. It causes severe head pain that is often accompanied by sensitivity to light, sound, or smells. Common symptoms of migraine are: Eye pain Sensi...

Pseudomyxoma peritonei is a rare malignant growth characterized by the progressive accumulation of mucus-secreting (mucinous) tumor cells within the abdomen and pelvis. The disorder develops after a small growth (polyp) located within the appendix...

Norovirus is a highly contagious virus that causes gastroenteritis, which is inflammation of the stomach and intestines. It is commonly referred to as the "stomach flu" or "winter vomiting bug" because it often causes symptoms such as vomiting, di...

A norovirus is a small virus that contains RNA and is surrounded by a protein coating. By sequencing the RNA, scientists have discovered that there are many different types of norovirus. Originally, strains were named based on the city in which th...

Pineal cysts are benign (non-cancerous) fluid-filled sacs located in the region of the brain that contains the pineal gland. Small pineal cysts (.5 cm or smaller) are common occurrences, often found incidentally on routine neurological exams. Smal...

Preeclampsia is a pregnancy complication characterized by high blood pressure and signs of damage to another organ system, most often the liver and kidneys. Preeclampsia usually begins after 20 weeks of pregnancy in women whose blood pressure had ...

A pituitary tumor is a tumor that forms in the pituitary gland near the brain that can cause changes in hormone levels in the body. This illustration shows a smaller tumor (microadenoma). Pituitary tumors are abnormal growths that develop ...

Pseudotumor cerebri literally means "false brain tumor." It is likely due to high pressure within the skull caused by the buildup or poor absorption of cerebrospinal fluid (CSF). The disorder is most common in women between the ages of 20 and 50....

Radiation sickness describes the harmful effects--acute, delayed, or chronic--produced by exposure to ionizing radiation. An observable effect due to radiation exposure becomes quite certain after a single dose of several hundred rads. As a rule, ...

Radiation sickness describes the harmful effects--acute, delayed, or chronic--produced by exposure to ionizing radiation. An observable effect due to radiation exposure becomes quite certain after a single dose of several hundred rads. As a rule, ...

Radiation sickness is damage to your body caused by a large dose of radiation often received over a short period of time (acute). The amount of radiation absorbed by the body — the absorbed dose — determines how sick you'll be. ...

Radiation sickness describes the harmful effects--acute, delayed, or chronic--produced by exposure to ionizing radiation. An observable effect due to radiation exposure becomes quite certain after a single dose of several hundred rads. As a rule, ...

Budd-Chiari syndrome is a rare disorder characterized by narrowing and obstruction (occlusion) of the veins of the liver (hepatic veins). Symptoms associated with Budd Chiari syndrome include pain in the upper right part of the abdomen, an abnorma...

Japanese Encephalitis is a severe inflammation of the brain caused by the Japanese B Encephalitis Virus that is transmitted by the bite of infected mosquitoes in certain areas of the world, particularly Asia. This disorder most commonly affects ch...

Salmonellosis is a type of food poisoning caused by the Salmonella bacteria. It is typically contracted by consuming contaminated food or water. Symptoms of salmonellosis include diarrhea, fever, abdominal cramps, and vomiting. In most cases, the ...

Sick building syndrome is believed by some to be an illness caused by unknown agents in buildings. Sick building syndrome is a controversial subject because many experts do not think it is a true syndrome. Sick building sy...

Spinal headaches are a fairly common complication in those who undergo a spinal tap (lumbar puncture) or spinal anesthesia. Both procedures require a puncture of the membrane that surrounds the spinal cord and, in the lower spine, the lumbar and s...

Introduction The superior vena cava is a large vein located in the upper chest, which collects blood from the head and arms and delivers it back to the right atrium of the heart. If this vein is compressed by outside structures, or if a th...

Systemic mastocytosis (mas-to-sy-TOE-sis) is a disorder that results in an excessive number of mast cells in your body. Mast cells normally help protect you from disease and aid in wound healing by releasing substances such as histamine and leukot...

Cryptococcosis is caused by a fungus known as Cryptococcosis neoformans. The infection may be spread to humans through contact with pigeon droppings or unwashed raw fruit. Contact with an infected individual may also spread the infection. Individu...

Torulosis is an airborne disease. It is more famously referred to as cryptococcosis. When you inhale infected dust, torulosis slowly spreads throughout your lungs, presenting as pneumonia. It could potentially be fatal. Sometimes, i...

Travelers' diarrhea is defined by most experts as three or more unformed stools in a 24 hour time period, passed by a person who is traveling. Travelers' diarrhea is commonly accompanied by abdominal cramps, nausea, and bloating. Travelers' diarrh...

Trichinosis (trik-ih-NO-sis), sometimes called trichinellosis (trik-ih-nuh-LOW-sis), is a type of roundworm infection. These roundworm parasites (trichinella) use a host body to live and reproduce. These parasites infect animals such as bears, cou...

Acetaminophen is a very safe drug when taken as directed, even for people with liver disease. Nevertheless, every drug carries risks. Liver damage from acetaminophen, which can be severe, can result either from an overdose or from r...

Peptic ulcers are open sores that develop on the inside lining of your stomach a...

Gilbert syndrome is a mild genetic liver disorder in which the body cannot properly process bilirubin, a yellowish waste product that is formed when old or worn out red blood cells are broken down (hemolysis). Individuals with Gilbert syndrome hav...

Cholinergic urticaria is a relatively common disorder of the immune system characterized by an immediate skin reaction (hypersensitivity) to heat, emotional stress, and/or exercise. Symptoms of the disorder include the appearance of distinctive sm...

Nephrogenic diabetes insipidus (NDI) is a rare kidney disorder that may be inherited or acquired. NDI is not related to the more common diabetes mellitus (sugar diabetes), in which the body does not produce or properly use insulin. NDI is a distin...

Congenital wandering spleen is a very rare, randomly distributed birth defect characterized by the absence or weakness of one or more of the ligaments that hold the spleen in its normal position in the upper left abdomen. The disorder is not genet...

Weil syndrome, a rare infectious disorder, is a severe form of the bacterial infection caused by Leptospira bacteria known as leptospirosis. Weil syndrome is characterized by dysfunction of the kidneys and liver, abnormal enlargement of the liver ...