Although shortness of breath is a natural response to situations such as exercise or stress, it may also be a symptom of a more serious underlying condition. These conditions are often related to the heart (e.g., mitral valve or heart muscle diseases) or the lungs (e.g., asthma).
A person whose heart or lungs are weak may become short of breath because these organs cannot meet the body’s oxygen needs. Therefore, anyone who regularly experiences shortness of breath for no apparent reason, or shortness of breath with less strenuous activity or at rest, is encouraged to see a physician to determine the cause. Also, any heart patient who experiences sudden shortness of breath for no apparent reason is urged to seek medical attention immediately.
Shortness of breath cannot be treated until the underlying condition is known. To help diagnose this condition, physicians have developed detailed question protocols designed to help them narrow the cause. Treatments vary depending on the cause.
About shortness of breath
Also known as dyspnea, shortness of breath is the feeling that one is not getting enough air. It may leave the person gasping. The person may want/need to breathe in more rapidly (tachypnea), deeply, or to blow out more completely. The individual may also feel the need to stop moving, sit down or lie down to catch the breath. Shortness of breath is sometimes described by patients as “hunger for air” or “chest tightness.”
Shortness of breath occurs when the heart or the lungs (or both) are unable to exchange enough carbon dioxide for oxygen. As a person inhales, oxygen enters the lungs. The air is then transported by red blood cells to the heart and distributed throughout the body. Red blood cells exchange fresh oxygen for carbon dioxide, which is a waste product, and the heart then transports this waste gas to the lungs to be expelled when the person exhales. If any part of this system is compromised, shortness of breath may result.
Any heart disease patient who suddenly feels short of breath for no apparent reason is urged to seek medical attention immediately.
Heart-related causes of shortness of breath
Shortness of breath may be due to an underlying cardiovascular or lung condition, such as the following:
Heart failure. A serious chronic condition in which the heart does not pump enough to meet the body’s need for oxygen. Shortness of breath is one of the earliest symptoms of heart failure.
Valvular heart disease (e.g., valvular stenosis or valvular regurgitation). This condition may occur in any of the four valves of the heart: the aortic valve, the mitral valve, the tricuspid valve or the pulmonary valve. Normally, these valves allow blood to flow in only one direction and only at the right time during a heartbeat. Valvular heart disease can lead to blood flow being restricted due to a narrowed valve (stenosis), or blood flow leaking in the wrong direction (regurgitation). Shortness of breath can occur as a result of the restricted or misdirected blood flow.
Coronary artery disease. This is a chronic disease in which there is a “hardening” (atherosclerosis) of the arteries on the surface of the heart. These arteries supply the heart with fresh, oxygen-rich blood. Atherosclerosis causes the arteries to become so narrowed and stiff that they block the free flow of blood. This reduced blood flow can cause shortness of breath.
Disease of the heart muscle (e.g., cardiomyopathy. Any disease of the heart muscle will decrease the heart's ability to effectively pump blood to the lungs and the rest of the body. Shortness of breath is one result.
Increased stiffness of the heart (diastolic dysfunction), resulting in increased pressure within the heart and the lungs. This is related to hypertrophy of the heart, diabetes mellitus, coronary artery disease and certain types of cardiomyopathy.
Cardiac tamponade. An emergency condition involving rapid buildup of fluid in the pericardium (the sac surrounding the heart).
Deep vein thrombosis and embolism, including pulmonary embolism.
Among women, shortness of breath may be an important warning symptom of heart disease or impending heart attack. Women tend to experience the symptoms of heart disease (such as angina) differently from men. Women who experience unusual fatigue or shortness of breath, even without angina, may be suffering from coronary artery disease. Men having a heart attack may also experience shortness of breath or shallow breathing, with or without chest pain.
Other causes of shortness of breath
Shortness of breath can occur for several non-heart-related reasons, many of which are temporary and not harmful. For example, shortness of breath is common after periods of heavy exertion, such as exercise. Exercise increases the amount of carbon dioxide (a waste product) in the blood. When the heart and breathing rate speed up, the lungs must handle an increased amount of carbon dioxide in the blood.
The lungs exchange carbon dioxide (which is exhaled from the body) with fresh oxygen in the blood. Now oxygen-rich, the blood leaves the lungs to nourish the body. If the heart and breathing rate cannot exchange enough carbon dioxide for oxygen, then the person may feel short of breath.
Shortness of breath is also common during or immediately after periods of stress, anxiety or fear. This is due to stress hormones (e.g., adrenaline), which can increase heart rate and breathing rate just like exercise. However, when people regularly feel short of breath for no apparent reason, a potentially serious underlying disorder may be responsible.
Shortness of breath that is not related to exercise, stress or a heart condition may be the result of:
Pulmonary embolism. This is a condition in which a blood clot has become lodged in a blood vessel of the lung, blocking blood flow to the lung and causing shortness of breath.
Emphysema and chronic bronchitis
Anemia
Thyroid disease
Some types of cancer, such as lung cancer and esophageal cancer
Asthma (may be accompanied with moderate to severe wheezing)
Some medications (e.g., nonsteroidal anti-inflammatories [NSAIDs], aspirin and beta blockers, particularly in persons with asthma)
Pneumonia
Obesity (a body mass index greater than 30)
Allergies, or an allergic reaction
Sleep apnea
Treatment options for shortness of breath
Before treatment can be prescribed, the physician will need to know what is causing the shortness of breath. Because people describe shortness of breath in a variety of ways, physicians have developed detailed questionnaires to help narrow the diagnosis. In addition, physicians may run tests that include a chest x-ray (which produces a picture of the general size, shape, and structure of the heart and lungs) and/or an electrocardiogram (which painlessly measures the electrical activity of the heart). Depending on the results of these tests, other tests that may be run include:
Echocardiogram. A test that uses sound waves to visualize the structures and functions of the heart. A moving image of the patient's beating heart is played on a video screen, where a physician can study the heart's thickness, size and function. The image also shows the motion pattern and structure of the four heart valves, revealing any potential leakage (regurgitation) or narrowing (stenosis). During this test, a Doppler ultrasound may be done to evaluate cardiac blood flow, and intra-cardiac pressure.
Pulmonary function test. A painless strategy for determining how well the lungs are functioning by measuring how much air the lungs can hold and how fast air can be moved out of the lungs.
Once the cause of the shortness of breath has been determined, then appropriate treatment can begin.
Medications may be prescribed to control symptoms. Also, lifestyle changes (e.g., less strenuous physical activity or weight loss) may help relieve the symptoms of the underlying disorder. The type of treatment will always depend on the cause of the shortness of breath (e.g., a heart or lung disease).
Prevention methods for shortness of breath
The best strategy for preventing shortness of breath is to prevent or treat the underlying conditions that cause it (e.g., heart conditions and pulmonary conditions). Although people have no control over developing conditions such as asthma, there are strategies that may help avoid flare-ups or a worsening of the condition.
Strategies for maintaining heart health, as well as controlling sleep apnea and obesity, include:
Eating a heart-healthy diet that is low in fats and oils and cholesterol.
A routine regimen of moderate exercise, depending on an individual's overall health, is invaluable in maintaining a healthy cardiovascular system. Exercise keeps obesity at bay and strengthens the heart. It also lowers cholesterol levels and blood pressure. Furthermore, when accompanied by a low-fat diet, exercise may help to reduce plaque deposits, reversing atherosclerosis. Even low-intensity leg exercises have shown benefit in relieving shortness of breath, particularly in heart failure patients in whom shortness of breath is a typical symptom.
Quitting smoking is critical for all smokers. People who smoke usually find that they experience regular shortness of breath. This may be caused by impairment of the lungs, the heart or both. Research from the U.S. Centers for Disease Control and Prevention (CDC) finds that smoking results in about 150,000 deaths from cardiovascular disease each year.
Controlling diabetes.
Controlling high blood pressure (hypertension).
Getting regular physical examinations, particularly if in a high-risk category for heart disease, can be an effective early warning system.
Strategies that may help to prevent or control upper respiratory infections or other pulmonary conditions include:
Protecting oneself from irritants in the air, including exhaust fumes, coal dust, air pollution, chimney smoke, secondhand tobacco smoke, hair spray and even heavy perfumes
Washing hands frequently
Keeping the home well-ventilated and free of mold
Getting an annual flu shot and regular pneumonia vaccines
Moving to a warmer climate
Questions for your doctor
Preparing questions in advance can help patients have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following questions about shortness of breath:
When does shortness of breath require medical attention?
When is it a medical emergency?
What is causing my shortness of breath?
How are my symptoms treated?
How is the underlying condition diagnosed and treated?
Can I prevent shortness of breath by improving diet, exercise or other habits?
Am I taking any medications that might cause shortness of breath?
Should I worry about shortness of breath that occurs after physical activity?
