When your immune system overreacts to an otherwise harmless substance like food, pet dander, pollen, or dust, this results in an allergy. Allergic responses can include everthing from sneezing, itchy, watery eyes, to life-threatening responses like difficulty breathing, low blood pressure, and anaphylaxis. Find expert information on the symptoms, causes, and medications used to treat allergies.

Allergy Basics

Health Overview Illustration - Allergies
What Are Allergies?

Treatment and Management

Female hand hold pack of yellow allergy medicine tablets
How Are Allergies Treated?
doctor giving patient a shot
What Are Allergy Shots?
Person blows their nose with a tissue at home.
6 Home Remedies To Stop Allergies

Explore Allergies

Pregnant person sitting on the couch itching allergic reaction rash on arm
What Is the Difference Between Anaphylaxis and Allergic Reaction?
Person using epinephrine auto injector in leg due to anaphylaxis
How Is Anaphylaxis Treated?
a person holding their chest and coughing
Signs and Symptoms of Mold Exposure
Symptoms of Anaphylaxis
Signs and Symptoms of Anaphylaxis
someone holding peanuts
What Causes a Peanut Allergy?
Person showing skin allergy rash to doctor
Food Allergies: Types, Symptoms, and Treatments You Need To Know
Head shot of young man having allergy symptoms, rubbing his eye with hand.
Do You Have These Unexpected Allergy Symptoms?
person coughing after eating a meal
Why Do You Cough After Eating?
Symptoms of a Garlic Allergy Composite
Garlic Allergy: What to Know
A man blows his nose into a tissue
What Is Allergic Rhinitis?
Doctor listening to patient's heart with stethoscope
Signs and Symptoms of Mast Cell Activation Syndrome (MCAS)
Person using inhaler outside due to allergic asthma
What Is Allergic Asthma?
woman scratching her back because of hypereosinophilic syndrome
What Is Hypereosinophilic Syndrome?
Woman looking at a pill bottle
When Is the Best Time To Take Allergy Medicine?
Senior woman opening a sealed packet of antihistamines
What Are Antihistamines?
Health Overview Illustration - Anaphylactic Shock
What Is Anaphylactic Shock?
Young man wearing a beanie hat with allergies and fever taking his temperature with a thermometer, lying on the living room couch.
Is Your Fever From Allergies?
Sick African American woman working from home office using laptop drinking hot beverage covered with blanket. Sickness and working concept.
What Are Seasonal Allergies?
woman with shirt lifted up to show visible bed bug bites on her back
Signs and Symptoms of Bed Bug Bites
A woman eating a pineapple
12 Foods That Can Cause An Itchy Roof of Mouth
Health Photo Composite - Postnasal Drip
What Is Post-Nasal Drip?
Man and woman sitting in a tree's shade by the water
What Is a Sun Allergy?
Patient talking to doctor about eye
Is It Pink Eye or Allergies?
healthcare provider taking eosinophils blood test
What Are Eosinophils—and What Level Indicates Cancer?
Health Overview Illustration - Anaphylaxis
What Is Anaphylaxis?
Lone Star Tick (Amblyomma americanum) on human skin
What Is Alpha-Gal Syndrome?
Allergies Photo Composite
Signs and Symptoms of Allergies
High view of five hands toasting with their drinks.
8 Rare Allergies To Know
A lone star tick on someone's skin
Do Tick Bites Cause a Red Meat Allergy? What to Know About The Rise of Alpha Gal Syndrome
Vans Gluten Free Waffle Recall
Van’s Gluten Free Waffles Recalled: FDA Says Product Could Pose Serious Allergy Risk
Most common food allergies
People of Color More Likely to Have Food Allergies Than White People, Study Finds
A man itches his arm
What Is a Maculopapular Rash?
Doctor examines hives on a patient's arm.
Signs and Symptoms of Hives (Urticaria)
A senior woman sits in the doctor's office and touches her chin while talking to a female dermatologist.
How Are Hives (Urticaria) Treated?
A man blows his nose
Why Nasal Congestion Happens—And How to Treat It
A man touches his throat with both hands
Why Your Throat Can Get Itchy—And How to Relieve It
Woman wearing a towel applying moisturizer.
Breaking Out in Hives: 4 Causes You Wouldn't Expect
Young Asian pregnant woman blowing nose with a tissue while sitting on a couch
Is My Stuffy Nose COVID-19? What You Need To Know
4 air purifiers on a carpet
The Best Air Purifiers for Allergies to Pollen, Pets & Smoke—After 3,000 Hours of Filtration
Person scratches itchy bites on their upper arm.
The Differences Between Bed Bug and Flea Bites on Humans
Person on a hike in the woods stops and swats at a mosquito on their arm.
What Is Skeeter Syndrome?
Close up of person scratching their neck where a small rash is.
3 Common Allergy Rashes
Portrait Of An Elderly Man A Headache While Standing In Garden
What Is an Allergy Headache?
Close-up of a fire ant
What Are Ant Bites?
Person lovingly pets their cat on the bed.
How To Treat a Pet Dander Allergy
person with sore throat sitting in bed touching neck
Can Allergies Cause a Sore Throat?
Wasp,hornet stings arm woman red swelling
Wasp Sting: What You Need To Know
Person outside sneezes into their tissue.
When Is Allergy Season?
Person making a bed.
8 Ways To Get Rid of Dust Mites
Person with swollen eyes from allergies.
What Are Swollen Eyes From Allergies—and How Do You Treat Them?
Female sitting on couch under a blanket blowing her nose
7 Differences Between Allergies and a Cold
mold-flood-disaster-cleaning-hurricane
What Does Mold Smell Like?
Stressed young Indian businessman getting sick while working overtime at home late at night
5 Reasons Allergies Are Worse at Night and What You Can Do
lone-star-tick-arm
What Are Lone Star Ticks?
person spraying perfume on wrist
Why Am I So Sensitive to Smells? Fragrance Allergy Symptoms To Know
Person looks out of a rainy window.
What To Know About Being Allergic to Water