Chest pain is a well-known indicator of heart disease, but it is far from the only one. Another important symptom to watch for is shortness of breath, which can feel like you’re exerting yourself more than usual. This can indicate heart valve disease, a heart attack, or heart failure, among other cardiovascular issues.

Shortness of breath, also known as dyspnea, can manifest in a variety of ways, including difficulty breathing, air hunger, a sense of suffocation, or intense tightening in your chest.

Most cases of shortness of breath are caused by a heart or lung problem. This is because the heart and lungs help carry oxygenated blood to tissues throughout the body, as well as remove carbon dioxide. Issues with either function can cause breathing problems.

A generally healthy person may experience shortness of breath while exercising or spending time in extreme temperatures or high altitudes, especially if they haven’t exercised recently. Shortness of breath should not be ignored, especially if it is severe and occurs suddenly.

Cardiovascular problems that cause shortness of breath can occur suddenly or gradually over time. However, a few factors can help you determine if your heart is in trouble:

1. You’ve noticed other potentially concerning signs.

How does your body feel? If you have a heart rhythm problem, you may experience heart palpitations, anxiety, lightheadedness, chest pain, or extreme fatigue. Meanwhile, shortness of breath caused by heart failure is frequently associated with leg swelling or breathlessness when lying down at night. Artery diseases can cause chest pain and heaviness, as well as shortness of breath.

In general, if you have any chest pain, tightness, or pressure that is associated with shortness of breath, you should see a doctor as soon as possible. If you’re already feeling short of breath, pain, numbness, weakness in your arms or legs, and pain in your jaw, neck, or throat are all red flags. (It’s also worth noting that you might not notice any symptoms at all—and women are more likely to experience nontraditional heart-related symptoms.)

2. You’re not exerting yourself when shortness of breath hits.

Keep track of when you experience shortness of breath. Is it after a strenuous workout or when you’re clearly exerting yourself more than usual? Or does it happen when you’re not pushing yourself at all? While some heart conditions can cause you to feel short of breath when walking or climbing a flight of stairs, they can also cause you to feel breathless when you lie down at night.

If shortness of breath occurs when you are clearly not exerting yourself, when you are doing something you could normally do without feeling winded, or if it occurs suddenly, these are warning signs that a heart problem may be to blame.

3. You already have an elevated risk of heart disease.

Suppose you’re trying to determine whether shortness of breath is a cause for concern. In that case, you should consider whether you have any risk factors that make you more susceptible to cardiovascular problems. Pregnancy, smoking, high blood pressure (also known as hypertension), diabetes, high cholesterol, kidney disease, or a history of heart attack or other heart issues are all examples (including being born with a heart condition).

According to the CDC, a lack of exercise or a poor diet may also play a role, but these factors are complicated and require careful consideration of a person’s circumstances. (Weight, and particularly BMI, is not a black-and-white indicator of heart health. More information can be found here.) Discuss your risk of heart disease with your doctor; they will carefully consider your medical history and discuss anything you should be aware of during your annual checkups.