cold vs. allergies

If you have allergies, your immune system mistakes a substance that is ordinarily harmless to most people as a threat and goes into defense mode. These substances, that can come from sources like pollen, pet dander, mold and dust mites are called allergens. Your allergies are not contagious. 

A cold happens when a virus makes its way into your body. Your immune system responds to this foreign invader by attacking the virus. Some of the cold symptoms, like runny nose and nasal congestion, can feel a lot like allergies so it can be hard to tell the difference. A cold is contagious. You can catch it when someone with a cold sneezes, coughs or touches you.1 2

While colds and allergies can have similar symptoms, here are some questions to help you tell if you need to reach for a antihistamine or curl up with a bowl of chicken noodle soup and binge watch your favorite shows:

Allergy symptoms tend to hit all at once when you come into contact with an allergen. Symptoms of a cold usually appear one at a time and develop slowly over a few days.

Colds typically run their course within 7-10 days. Allergy symptoms can last weeks or months, and will be present as long as you are exposed to the allergen. If your cold symptoms last longer than 10 days, talk to your doctor.

Runny nose and sneezing are common symptoms of both colds and allergies. But you can often tell the difference by looking at the color and texture of your mucus. If you have allergies, your mucus will typically be clear, thin and watery. If you have a cold, the mucus from coughing or sneezing may be thick and yellow or green. Yellow or green mucus could indicate an infection requiring medical attention.

Colds may come with slight body aches and pains. Allergies are not usually associated with body aches and pains.

Colds are more common during the winter months,but could also occur any time of the year. Indoor allergies can happen year-round and outdoor seasonal allergies are more common in the spring through fall when pollen counts are high.1 

6. Do You have watery, itchy Eyes?

Itchy watery eyes are common with allergies and rare with a cold.

7. Do you have a fever?

Fever is not associated with allergies, but may be present with a cold.

8. Do you have an itchy nose?

Colds don't make you itch. Allergies can.

9. Is your appetite the same?

A cold can decrease your appetite. Allergies usually don't.

10. Do you have sneezing attacks?

If you sneeze lots in a row, it's most likely allergies.

This doesn't happen as much with a cold.

1. Treatment of the Common Cold in Children and Adults. American Family Physician. Accessed December 27, 2017.
2. Common Colds: Protect Yourself and Others. Centers for Disease Control and Prevention. Accessed December 27, 2017.
3. Allergies: Questions & Answers. Cleveland Clinic. Accessed November 5, 2017.