Why give?

Ask a cardiologist: Shortness of breath

Q: I feel winded after a few minutes of stair climbing or brisk walking. Could I have a heart condition?
Tired young woman catching her breath after a long run

A: Probably not. Feeling short or out of breath is a common symptom that overlaps with many conditions. In most cases it has nothing to do with your heart.

What it might be

Typically, only one in 100 people who experience shortness of breath after physical exertion have a heart condition. And the other 99? Some of it is a natural change that comes with aging or being too sedentary. Shortness of breath is also linked to anemia, lung conditions (bronchitis, emphysema, asthma), smoking history, lack of sleep, stress, and a number of other potential conditions. Expect your doctor to ask you about your lifestyle or even run a blood test to narrow down the underlying cause.

The good news is a symptom like this isn’t as worrisome as it was 60 or even 30 years ago. We’ve done a great job at improving early screening, diagnostic testing and treatments.


When it is your heart

Shortness of breath can be an early sign of heart failure. Traditionally, we think of heart failure as a heart that’s too weak to pump blood. But there’s another type, known as diastolic dysfunction, where the heart muscle can’t relax. When we’re talking about shortness of breath, it’s more likely that we’re dealing with a relaxation problem. A heart muscle that is constantly flexed changes shape and can thicken over time (like any muscle), making it paradoxically harder rather than easier for your heart to pump blood and move oxygen through your body. 

What happens next

If we detect an underlying heart condition, we’ll check for risk factors that may predispose you to stiffening of the heart muscle, like high blood pressure or diabetes.  Changes to diet and an increase in physical activity can significantly help lower these risk factors. If after a good effort your risk is still high, your doctor may recommend medication or when necessary a cardiac test/procedure. Occasionally we find that there was an injury to the heart muscle that weakened or stiffened it, like a heart attack that the patient may or may not have realized occurred in the past. Sometimes shortness of breath may indicate an active condition where there’s an inadequate supply of oxygen to the heart muscle from a severely blocked coronary artery. Other times a disturbance in the heart’s beat-to-beat rhythm may be the culprit for shortness of breath. There are other heart-related injuries that cardiac testing can also detect and treat. When a weakened or stiff heart muscle is caused by a genetic condition, we recommend screening for the patient’s closest relatives (children, parents and siblings). The earlier we can detect a potentially serious condition, the sooner we can get it under control.

Emerging research coming out of our collaborative BREATH program based at Mount Sinai Hospital with support from Toronto General Hospital and Women’s College Hospital all in Toronto, could reshape how we screen (and ultimately treat) heart failure. Led by Dr. Susanna Mak, a previous Foundation-funded researcher, this promising research uses sophisticated technology to detect subtle changes within the heart muscle at the earliest stages. Early detection is especially important for patients dealing with a heart relaxation problem, because this requires different treatments from those that help patients with a weakened heart muscle.

One thing that we almost always prescribe is moderate exercise. It’s one of the best therapies we can offer. No matter what the underlying condition is, when patients introduce exercise into their lives they increase their endurance. Gradually, they can do more activity with less shortness of breath.

I’d recommend exercise even if the tests come back all clear. If it’s a symptom that had you worried, it’s important to be honest with yourself – not hard on yourself. Most Canadians don’t get the recommended amount of physical activity. If you’re one of them, it’s never too late to increase your physical activity, a little bit at a time.

Dr Jay Udell stands before a white screenDr. Jay Udell is a cardiologist at Women’s College Hospital and the Peter Munk Cardiac Centre of the University Health Network, and a clinician-scientist at the Women’s College Research Institute and Faculty of Medicine, University of Toronto. He received a 2015 CP Has Heart Cardiovascular Research Award through Heart & Stroke to study the impact of failed fertility treatment on women’s heart health.

  • Do you have a question for our cardiologist? Send it to Unfortunately we cannot provide personal replies. Questions of general interest will be answered in future Heart and Stroke Foundation publications. 

This article is for informational purposes only and is not a substitute for medical advice, a medical diagnosis or treatment from a physician or qualified healthcare professional. The Heart and Stroke Foundation of Canada assumes no responsibility or liability arising from any error in, or omission of, information, or from the use of any information or advice contained in this article.