What are allergies?

Allergies happen when your immune system reacts to something that is usually harmless. These substances—called allergens—can include pollen, dust, certain foods, or pet dander.

Instead of ignoring these triggers, your body treats them as threats and releases chemicals that trigger symptoms.

Common causes and triggers:

• Pollen from trees, grass, or weeds
• Dust mites or mold
• Animal dander
• Foods such as nuts, dairy, or shellfish
• Medications or insect stings

Allergies often run in families, but they can develop at any age.

Symptoms

Allergy symptoms can affect different parts of the body and may range from mild to severe.

Common symptoms include:

• Sneezing or a runny, stuffy nose
• Itchy or watery eyes
• Skin rashes, hives, or itching
• Coughing, wheezing, or shortness of breath

In rare cases, allergies can cause anaphylaxis, a serious reaction that may lead to swelling, trouble breathing, or a sudden drop in blood pressure.

How is it diagnosed?

A healthcare provider will begin by asking about your symptoms and medical history. They may recommend testing to identify specific triggers.

Common tests include:

• Skin testing: Small amounts of allergens are placed on the skin to check for reactions
• Blood tests: Measure how your immune system responds to certain allergens
• Challenge tests: Carefully monitored exposure to a suspected allergen when needed

These tools help pinpoint what’s causing your symptoms so care can be tailored to you.

How is it treated?

Treatment focuses on reducing symptoms and preventing reactions.

First steps often include:

• Avoiding known triggers when possible
• Using medications such as antihistamines or nasal sprays

If symptoms continue:

• Allergy shots (immunotherapy) may help your body become less sensitive over time
• Oral immunotherapy may be an option for certain allergens

For severe allergies:

• Emergency medication like epinephrine may be prescribed

With the right plan, most people can control symptoms and live comfortably.