What Are Hives?

Hives, also known by the medical term urticaria, are itchy, raised welts on the skin that typically appear as an allergic response. These welts can be red, pink, or skin-colored and may appear suddenly anywhere on the body. While many cases are mild and resolve on their own, some individuals experience chronic hives, which persist or reoccur for six weeks or longer.

Urticaria affects approximately 20% of people at some point in their lives. Though not usually dangerous, hives can greatly interfere with quality of life—especially when they’re frequent or severe. Understanding what triggers hives and how to manage them is key to reducing discomfort and preventing flare-ups.

Types of Hives

Hives are categorized based on how long they last and what causes them. This classification plays a crucial role in diagnosis and treatment.

Acute Hives

Acute urticaria refers to outbreaks that last less than six weeks. These are often short-lived and may be linked to:

  • Food allergies (e.g., shellfish, nuts, eggs)

  • Infections (especially viral in children)

  • Medications like antibiotics or NSAIDs

  • Insect stings

  • Physical triggers like heat or cold

About two-thirds of hives cases are acute and often resolve without treatment.

Chronic Hives

Chronic urticaria occurs when symptoms last longer than six weeks or recur regularly. The majority of chronic hives cases are chronic spontaneous urticaria, meaning the trigger is unknown (idiopathic). These cases are more common in adults, particularly women, and are sometimes associated with autoimmune conditions.

Inducible Hives

Also known as physical urticaria, inducible hives are caused by specific physical stimuli such as:

  • Pressure or friction on the skin

  • Cold or hot temperatures

  • Water exposure

  • Sunlight (solar urticaria)

  • Exercise or sweating

  • Latex or certain fabrics

Roughly 20–30% of chronic urticaria cases are inducible.

Symptoms of Hives

Hives can manifest in several ways. Most symptoms are confined to the skin, but some may involve deeper tissues or the entire body.

Wheals

Wheals are the hallmark of urticaria. These welts can be round, oval, or irregularly shaped, typically reddish or darker than your skin tone. They:

  • Vary in size from a few millimeters to several centimeters

  • Appear and disappear quickly, often within 24 hours

  • Can occur anywhere but are common on areas exposed to pressure

  • Often feel warm or slightly swollen

  • May appear skin-colored on darker skin tones

Itching

Intense itching (pruritus) is one of the most uncomfortable symptoms. Itching can:

  • Occur with or without visible welts

  • Worsen at night

  • Lead to scratching, which may irritate the skin further

Angioedema

In about 40% of hives cases, angioedema—a deeper swelling under the skin—also occurs. This is most common in:

  • Eyelids

  • Lips

  • Hands and feet

  • Throat (in rare but serious cases)

Angioedema may cause tightness, discomfort, or pain. If the throat swells, it can become a medical emergency.

Other Systemic Symptoms

Though less common, chronic urticaria may come with:

  • Fatigue

  • Nausea or abdominal cramps

  • Headaches

  • Joint swelling

  • Flushed skin

  • Rapid heartbeat (palpitations)

  • Difficulty breathing

These symptoms often signal more severe or systemic involvement.

Causes and Triggers

Hives occur when mast cells in the skin release histamine and other chemicals in response to a trigger, leading to swelling, redness, and itchiness.

Common Triggers

  • Food allergens: peanuts, shellfish, eggs, dairy

  • Medications: NSAIDs, antibiotics, aspirin

  • Infections: bacterial or viral (common in children)

  • Environmental triggers: pollen, animal dander, mold

  • Insect bites or stings

  • Physical factors: heat, cold, friction

  • Stress or emotional upset

  • Hormonal changes

  • Autoimmune disorders

Sometimes, no identifiable cause is found. In such cases, the hives are called idiopathic.

Risk Factors

While anyone can develop hives, certain factors raise your risk:

  • Age: Acute hives are more common in young children

  • Sex: Women are more likely to develop chronic urticaria

  • Autoimmune disorders: such as thyroid disease or lupus

  • Previous allergic reactions

  • Family history of hives or allergies

  • High-stress lifestyle

Diagnosis

Diagnosing hives involves a combination of clinical observation and medical history.

Physical Examination

A healthcare provider will:

  • Examine wheals, angioedema, and other symptoms

  • Check vital signs (heart rate, breathing, blood pressure)

  • Ask about recent exposures or medications

  • Evaluate for signs of dermographism—hives that appear after the skin is stroked or scratched

Allergy and Blood Testing

In chronic or severe cases, tests may help identify underlying causes:

  • Skin prick tests: identify allergic reactions to specific substances

  • Blood tests: check levels of eosinophils, IgE, or tryptase

  • Challenge testing: controlled exposure to cold, pressure, or other physical triggers

  • CBC or ESR: assess for systemic inflammation or infection

Treatment Options

For many people, hives resolve without treatment. When necessary, the goal is to relieve symptoms and prevent flare-ups.

Antihistamines

These are the first-line treatment for most hives:

  • OTC options: cetirizine (Zyrtec), loratadine (Claritin), fexofenadine (Allegra)

  • Prescription options: hydroxyzine (Vistaril), diphenhydramine (Benadryl)

Antihistamines work by blocking the histamine released by mast cells, reducing itching and swelling.

Corticosteroids

In cases where antihistamines are insufficient, oral corticosteroids like prednisone may be prescribed short-term to reduce inflammation.

Biologics and Other Medications

For chronic or treatment-resistant hives:

  • Omalizumab (Xolair): a monoclonal antibody that blocks IgE

  • Leukotriene antagonists: such as montelukast (Singulair) or zafirlukast (Accolate)

  • Antacids: sometimes used in combination with antihistamines for added relief

Lifestyle Adjustments and Trigger Avoidance

Preventing hives often involves identifying and avoiding your unique triggers:

  • Avoid heat, sun, or cold exposure if you're sensitive

  • Switch medications if NSAIDs or antibiotics are a problem

  • Wear breathable, non-irritating fabrics

  • Manage stress through relaxation, therapy, or exercise

  • Avoid alcohol and known allergens

Prevention Strategies

Though hives can't always be prevented, some habits may reduce your risk:

  • Keep a symptom diary to track flare-ups and potential triggers

  • Consult with an allergist for long-term management

  • Prioritize mental wellness—stress is a common trigger

  • Avoid harsh skin products or irritants

  • Maintain a consistent sleep schedule to support immunity

Related Health Conditions

Chronic hives may be linked with or mimic symptoms of other conditions, such as:

  • Asthma

  • Eczema (atopic dermatitis)

  • Thyroid disease

  • Rheumatoid arthritis

  • Vitiligo

  • Diabetes

  • Osteoporosis (less common but suggested in some research)

  • Mental health concerns: anxiety, depression, sleep disturbance

These associations highlight the importance of holistic care.

Living With Hives

Although hives are rarely life-threatening, they can take a toll on physical comfort and emotional well-being. Chronic urticaria may interfere with:

  • Sleep due to nighttime itching

  • Work or school productivity

  • Social interactions due to visible welts

  • Self-confidence and mental health

Talking openly with healthcare professionals, following a treatment plan, and seeking mental health support when needed can improve quality of life significantly.

When to See a Doctor

Seek immediate medical care if:

  • Your hives last more than a few days or recur often

  • You have swelling in the throat or difficulty breathing (possible anaphylaxis)

  • OTC medications don’t relieve symptoms

  • You develop systemic symptoms like nausea, dizziness, or fainting