In-depth

Complications

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.

Symptoms

Anaphylaxis

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

Hives and angioedema

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

Nausea and vomiting

Sick to your stomach? Nausea and vomiting usually pass quickly but sometimes result from long-term or serious conditions.

Runny nose

Runny nose: What's causing your sniffles?

Shortness of breath

Shortness of breath can be frightening. Most of the time, a heart or lung condition is the cause.

Tachycardia

Tachycardia, a rapid heart rate, is caused by an abnormality in your heart's electrical impulses. Tachycardia can cause serious complications, including sudden cardiac arrest.

Tests and diagnosis

Allergy skin tests

Itching, sneezing and swelling: Find out what's causing your allergy symptoms.

Jun. 27, 2012