Urticaria, commonly known as hives, causes itchy, raised welts (wheals) that can appear anywhere on the body and vary in size and shape. It is very common — affecting up to 20% of people at some point — and is usually harmless, though it can occasionally signal a more serious allergic reaction.

Symptoms of Urticaria

The main symptom is itchy, raised welts on the skin. Other signs include redness, swelling, a burning or stinging sensation, and warmth in the affected area.

What Causes Hives?

Hives have many possible triggers:

Allergies: to foods (nuts, shellfish, eggs, milk), medications, or insect stings.
Infections: bacterial, viral, or fungal — including strep throat, mononucleosis, and hepatitis.
Medications: such as aspirin, ibuprofen, antibiotics, and blood pressure drugs.
Physical factors: heat, cold, pressure, and exercise.
Stress: emotional stress can trigger hives in some people.
Other conditions: lupus, thyroid disease, and inflammatory bowel disease.

How Urticaria Is Diagnosed

Diagnosis is usually based on your medical history and a physical exam. Your doctor will ask about your symptoms and triggers, and may order blood or allergy tests to help identify the cause.

Treatment Options

Treatment depends on the cause and severity. Most acute hives clear on their own within hours or days, but if they are bothersome a doctor may recommend antihistamines (the most common treatment, blocking histamine), corticosteroids (to reduce inflammation in severe cases), or epinephrine (for anaphylaxis or severe reactions). For ongoing flare-ups, soothing products for sensitive skin can help comfort irritated skin.

Acute vs. Chronic Urticaria

Acute urticaria lasts less than 6 weeks and usually has an identifiable trigger like an allergy or infection. Chronic urticaria lasts longer than 6 weeks, and its cause is often unknown.

Conditions That Look Like Hives

Several conditions resemble urticaria: eczema (dry, itchy, inflamed skin), psoriasis (thicker, scaly patches), contact dermatitis (localized to where an irritant touched the skin), and insect bites (localized welts).

Prevention and Self-Care

If you know your triggers, avoid them. To ease symptoms, apply cool compresses, take a cool bath or shower, wear loose, comfortable clothing, avoid heat and humidity, resist scratching, and take antihistamines as directed by your doctor. People with chronic urticaria may need longer-term medication to stay in control.

Natural Remedies

Some evidence supports gentle remedies alongside medical care: aloe vera for its anti-inflammatory, soothing properties; quercetin (a natural antihistamine found in onions, apples, and berries); vitamin C as an antioxidant that may reduce inflammation; and probiotics, which may help reduce the frequency and severity of hives.

Sun Protection

Sun exposure can trigger hives in some people, so wearing sunscreen and protective clothing is a simple, effective precaution.

When to See a Doctor

See a doctor if your hives are severe or persistent, interfere with daily life, or may be caused by a medication. Seek urgent care if you have difficulty breathing; swelling of the face, lips, or tongue; or dizziness — these can be signs of a serious allergic reaction.