Nothing can break your post-run euphoria quite like a coughing fit. But why are you hacking now when you breathed just fine during your workout?

Coughing during or after exercise is a common symptom of a condition called exercise-induced bronchoconstriction (EIB), which occurs when the airways in your lungs narrow temporarily in response to any kind of physical activity that revs up your heart rate.

“This makes it more difficult for the air to get through into the lungs,” says Jonathan Parsons, M.D., director of the Ohio State University Multidisciplinary Cough Program.

It’s similar to what happens to your lungs during asthma. In fact, EIB used to be known as “exercise-induced asthma.” But unlike asthma, where attacks can be triggered by a variety of things like smoke, pollen, mold, pet dander, or viruses, EIB is sparked only by exercise.

Most asthmatics have suffered EIB symptoms during some point in their lives, says Dr. Parsons. So if you have asthma, you may already know exercise can cause some distress.

But EIB can affect up to an estimated 15 percent of the general, asthma-free population. Here’s how to spot the signs and treat the condition.

What Are the Symptoms?

Symptoms of EIB are nonspecific, meaning they’re similar to those caused by other conditions.

Common signs include shortness of breath, tightness in your chest, cough, wheezing, and difficulty getting air into your lungs. You might also feel like you have decreased endurance or abdominal discomfort.

The symptoms are often mild to moderate: You may just feel a slight wheeze or a bit of tightness in your chest—more of an annoyance than anything more serious.

But the attacks can also be severe, requiring you to stop what you’re doing to catch your breath. In some cases, you may even need to go to the emergency room to get your breathing back under control.

When Do You Get It?

Usually it takes about 10 to 15 minutes of exercise to provoke an EIB episode, Dr. Parsons says.

Any exercise that speeds up your heart rate can trigger the condition, though it’s much more common in endurance athletes, like runners and swimmers.

EIB pops up after short, intense bouts of exercise as well, like sprinting or even circuit training without rest periods.

The kind of air you breathe can play a role, too. EIB tends to flare more when the air lacks humidity, which is common on cold days. So that may be one reason why your outdoor runs have left you panting lately.

“Your lungs don’t like dry air,” says Dr. Parsons. “So the airways try to humidify it, and when they do, they become dehydrated. Dehydrated airways are irritable and much more likely to constrict or narrow.”