It's easy to get them confused. Just ask Paul Ehrlich, MD, a professor of pediatrics at New York University. He'd been an allergist for years when he came down with what he thought was a cold. "I'd had a watery, runny nose for several days when one of my patients took a look at me and said, 'Oh, you have allergies, too!'" Ehrlich says.
He'd never had allergies before, but a checkup with another doctor confirmed that the patient was right. "Turns out I was allergic to birch trees, which were in bloom at the time," he says.
A cold is an infection caused by a virus. Allergies are your immune system's reaction to a substance like pollen or pet dander. Because the two conditions cause similar symptoms, like sniffles and stuffiness, many people get them mixed up. Knowing which is which can help you get the right treatment, and that will help you feel better faster.
It's Probably Allergies If:
Your mucus is clear or watery. And it will stay clear, instead of becoming thick or discolored like it can with a cold, says Michael Benninger, MD, an ear, nose, and throat specialist at the Cleveland Clinic.
Your eyes are itchy or watery. It's rare to have itchy eyes when you have a cold.
Your symptoms stay the same. "Allergies may feel extra intense for the first day or 2, but you'll have the same symptoms day after day," Benninger says.
You've had the sniffles for more than a week. A cold usually clears up in 7 to 10 days, but allergies can last several weeks or longer.
Your symptoms show up only in certain situations. Find yourself sneezing every spring or fall? Those are common times for allergies. ( Colds and the flu usually show up in the late fall and winter.) Another allergy tip-off: Being in a specific place makes you feel miserable -- for example, in a house with a cat.