In-depth

Acute liver failure

Anaphylaxis

Anaphylaxis is the most serious type of allergic reaction. It often occurs rapidly after exposure to an allergen and may be life-threatening.

Aortic aneurysm

Appendicitis

Ascariasis

Barrett's esophagus

Bile reflux

Bladder stones

Bladder stones are small masses of minerals in your bladder — often forming as a result of an enlarged prostate, nerve damage or infection.

Blind loop syndrome

Botulism

Cardiogenic shock

Chagas disease

Chlamydia

Are you worried you might have chlamydia? Find out how this common sexually transmitted infection is diagnosed and treated.

Cholecystitis

Colon polyps

Crohn's disease

Cyclic vomiting syndrome

Cyclic vomiting syndrome can last for hours or days and shares many triggers with migraines.

Dengue fever

Diabetic ketoacidosis

Diabetic neuropathy

Diarrhea

Diarrhea can have many triggers, including viruses, bacteria, parasites and certain medications. Though unpleasant, most cases of diarrhea go away without treatment.

Diverticulitis

E. coli

Ectopic pregnancy

Egg allergy

Encopresis

Encopresis occurs when a child resists having bowel movements, causing stool to collect in the colon and rectum. Leakage of liquid stool also is common.

Enlarged liver

Eosinophilic esophagitis

Epididymitis

Esophagitis

Food allergy

Food allergy symptoms can make you miserable. Unfortunately, there's no cure — but there are steps you can take to keep your symptoms in check.

Food poisoning

Food poisoning has many forms, and some can be serious. Here's how to recognize food poisoning and ways to prevent getting sick.

Gallbladder cancer

Gallstones

Gallstones often don't cause symptoms. But if you have a gallbladder attack, you're not likely to forget it.

Gas and gas pains

Intestinal gas can be embarrassing and sometimes painful. But a few simple measures can often provide relief.

Giardiasis

Gonorrhea

Gonorrhea is a highly contagious sexually transmitted infection. Without treatment, serious complications can occur.

H. pylori infection

Hantavirus pulmonary syndrome

Hantavirus pulmonary syndrome is initiated by a rodent-carried virus that infects the lung tissues, bringing on flu-like symptoms, respiratory problems and even death.

Heart attack

Henoch-Schonlein purpura

Henoch-Schonlein purpura causes inflammation of small blood vessels (vasculitis) and often a purplish rash. It's most common in children ages 2 to 6.

Hepatitis A

Hepatitis B

Hives and angioedema

Hives and angioedema — Comprehensive overview covers symptoms, causes, treatment of these common allergic disorders.

Hypercalcemia

Hyperglycemia in diabetes

Inflammatory bowel disease (IBD)

Intestinal ischemia

Irritable bowel syndrome

Ischemic colitis

Kawasaki disease

Kawasaki disease — the leading cause of acquired coronary disease in children — causes artery wall inflammation throughout the body. It affects children younger than age 5.

Kidney infection

Lactose intolerance

Lead poisoning

Liver disease

Liver hemangioma

Liver hemangioma is the most common type of noncancerous (benign) liver mass. Learn how doctors treat liver hemangioma.

Mental illness

Mesothelioma

Milk allergy

Mittelschmerz

Non-Hodgkin's lymphoma

Norovirus infection

Noroviruses cause an intestinal flu-like illness that typically resolves within days. Norovirus infection is highly contagious, especially in closed settings like hospitals and cruise ships.

Ovarian hyperstimulation syndrome

Ovarian hyperstimulation syndrome (OHSS) — Comprehensive overview covers symptoms, treatment of this complication of infertility treatment.

Pancreatic cancer

Pancreatic cancer is often fatal. Find out which new treatments offer hope.

Pancreatic cysts

Pancreatitis

The pain of pancreatitis, an inflammation of the pancreas, can last for days, or in chronic cases, for years. Pancreatitis can lead to serious complications.

Pelvic inflammatory disease (PID)

Peritonitis

Pheochromocytoma

Pinworm infection

Placental abruption

Porphyria

Porphyria is a group of inherited disorders that result from buildup of natural chemicals call porphyrins, which can cause nervous system and skin problems.

Postpartum preeclampsia

Preeclampsia

Primary biliary cirrhosis

Primary sclerosing cholangitis

Proctitis

Salmonella infection

Salmonella infection will cause only diarrhea and stomach pain in some people, but for infants and immunocompromised people, this bacterial illness can cause life-threatening complications.

Scrotal masses

Shellfish allergy

Shigella infection

Symptom Checker

Foot pain? Headache? Sore throat? Skin rash? Use the Symptom Checker to find out what's causing your symptom.

Tapeworm infection

Testicular torsion

Toxic hepatitis

Toxic hepatitis is liver damage that occurs when your liver isn't able to break down certain toxins — including common pain relievers such as Tylenol.

Traveler's diarrhea

Traveler's diarrhea is unpleasant. Find out how to avoid this travel-related health problem.

Trichinosis

Typhoid fever

Ulcerative colitis

Vasculitis

Vesicoureteral reflux

Whipple's disease

Wilms' tumor

Yellow fever

Zollinger-Ellison syndrome

June 21, 2013