Acute coronary syndrome

Acute kidney failure

Acute liver failure

Addison's disease


Do you feel trapped in your own home? Do you worry about having a panic attack? Find out how agoraphobia can be treated.

Airplane ear

Alcohol intolerance

Alcohol poisoning

Alcohol use disorder

Alcoholic hepatitis

Alcoholic liver disease


Amniotic fluid embolism


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



Antibiotic-associated diarrhea



Autoimmune hepatitis

Bee sting

Benign paroxysmal positional vertigo (BPPV)

Bile reflux

Bird flu (avian influenza)

Blastocystis hominis infection

Blind loop syndrome


Brain aneurysm

Brain tumor

C. difficile infection

Carbon monoxide poisoning

Carcinoid tumors

Cardiogenic shock

Castleman disease

Celiac disease

Chagas disease

Chest pain



Cholera causes severe diarrhea and can kill in a matter of hours, yet can be easily treated with oral or intravenous fluids.

Chronic daily headaches

Chronic kidney disease

Chronic sinusitis

Churg-strauss syndrome


Colon polyps


Concussions can be serious injuries that need sufficient time to heal.

Congenital adrenal hyperplasia

Congenital adrenal hyperplasia is a genetic condition affecting the adrenal glands and interfering with normal growth and development in boys and girls.

Constipation in children

Cryptosporidium infection

Cryptosporidium infection may cause diarrhea in healthy people, but for people with HIV/AIDS and weakened immune systems, the illness can cause serious complications.

Cyclic vomiting syndrome

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

Cyclospora infection

Dengue fever

Diabetes insipidus

Diabetic coma

Diabetic ketoacidosis

Diabetic neuropathy


Drug allergy

Dumping syndrome


E. coli

Ear infection (middle ear)

Ebola virus and Marburg virus

Ectopic pregnancy

Egg allergy



Encephalitis is inflammation of the brain usually caused by a viral infection. Severe cases can cause brain damage, even death.


Enlarged liver

Eosinophilic esophagitis


Exercise headaches

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






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.

Headaches in children

Heart attack

Heart failure

Heat exhaustion


Hemolytic uremic syndrome (HUS)


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

Hepatitis C

Hirschsprung's disease



Hyperglycemia in diabetes


Infant reflux

Intestinal ischemia

Intestinal obstruction

Intracranial hematoma


Jellyfish stings

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 stones

Krabbe disease

Krabbe disease is a rare, inherited disorder — most often affecting infants — that impairs functioning of the central nervous system and usually leads to early death.

Lactose intolerance

Lead poisoning

Legionnaires' disease

Listeria infection

Most people exposed to listeria don't become ill. But for those at risk of a listeria infection — a foodborne illness — the consequences can be severe.

Liver cancer

Liver disease

Liver hemangioma

Low blood pressure (hypotension)

Low blood pressure (hypotension) can be a sign of good health or of a life-threatening condition. Find out more about hypotension's causes and treatment options.


MCAD deficiency


Menstrual cramps

A monthly period is bad enough. Add in painful menstrual cramps, and you may be cursing this thing called womanhood. How do you get relief?

Mesenteric lymphadenitis


Milk allergy

Molar pregnancy

Morning sickness

Multiple myeloma

Myocardial ischemia

Naegleria infection

Nonulcer stomach pain

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.


Orthostatic hypotension (postural hypotension)

Orthostatic hypotension (postural hypotension) is a form of low blood pressure that occurs when you stand up.

Ovarian cancer

Ovarian cysts

Ovarian hyperstimulation syndrome

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

Pancreatic cysts


Panic attacks and panic disorder

Parvovirus infection

Peanut allergy

Pelvic inflammatory disease (PID)

Peptic ulcer


Pinworm infection

Pituitary tumors



One of the most feared diseases of the 20th century, polio has been eradicated from the developed world but remains a threat in less developed nations.

Polymorphous light eruption

Polymorphous light eruption is a sun-induced skin rash affecting people who develop a sensitivity to sunlight.


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


Pseudomembranous colitis

Pseudotumor cerebri

Pyloric stenosis

Q fever

Radiation sickness

Recurrent breast cancer

Reye's syndrome

Rocky Mountain spotted fever


Ruptured eardrum

A ruptured eardrum causes hearing loss and can give bacteria easy access to your middle ear. A ruptured eardrum usually heals without treatment.

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.

Scarlet fever

Scarlet fever is a bacterial infection that causes a rash, fever and sore throat and usually affects children and adolescents.

Scrotal masses

Shaken baby syndrome

Shellfish allergy


Social anxiety disorder

Spider bites

Spinal headaches

Spontaneous coronary artery dissection (SCAD)

Staph infections

Stomach cancer

Strep throat

Sudden cardiac arrest

Swine flu (H1N1 flu)

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

Thunderclap headaches

Toxic hepatitis

Toxic shock syndrome

Traumatic brain injury

While mild traumatic brain injury generally results in few long-term problems, more severe injury can cause several physical, emotional, behavioral, communication and cognitive problems.

Traveler's diarrhea


Vasovagal syncope

Ventricular fibrillation

Wheat allergy

Whooping cough

Wilson's disease

Yellow fever

Zollinger-Ellison syndrome

Sept. 04, 2014