The cardiovascular system, the human body’s circulatory system, is a vital network of organs and tissues such as the blood, heart, and blood vessels responsible for transporting blood. The circulatory system plays an important role in the delivery of oxygen, nutrients, and hormones while removing waste products like carbon dioxide from the body. Shortness of breath or dyspnea is a common symptom of many cardiovascular diseases such as angina, heart attacks and manifests at all stages of heart failure. There are many other factors that can make people develop light or poor breathing patterns that are short-lived or not symptomatic for disease. For example, it is normal for a person to experience shortness of breath after strenuous exercise like running or walking up a flight of stairs. It is therefore important to discern shortness of breath when it is appropriate and when it is not. It is abnormal to experience shortness of breath after routine walking, walking a few steps, or while at rest. When dyspnea is inappropriate to the activity, it may be considered a symptom of heart disease or, in some cases, of another illness such as asthma. A change in symptoms is another sign that medical attention should be sought. Dyspnea should be of particular concern if it begins suddenly. The abrupt onset of dyspnea is often due to heart failure, whereas chronic shortness of breath is more likely to be a symptom of coronary artery disease, valvular heart disease or of another condition, such as chronic lung disease or emphysema. Dyspnea, however, may not always be easy to recognize, because it is a subjective symptom. Some individuals may experience inappropriate shortness of breath, yet be unaware of it or deny it, while others may appear to be breathing normally, yet feel short of breath. There are three basic types of dyspnea that are generally investigated when a doctor is making a diagnosis: cardiac, pulmonary, and functional (psychological). Cardiac dyspnea generally occurs when the heart’s pumping action has become weakened or in case of an obstruction of the free flow of blood through the heart into the blood vessels. Poor pumping quality can be due to weakened heart muscle caused by coronary artery disease. Narrowing of a valve between the heart’s pumping chambers can also prevent blood from flowing from chamber to chamber. If too little blood is pumped forward with each beat there is a buildup of pressure in the lungs. Diminished pumping quality creates shortness of breath because blood and fluids begin to back up. Pressure increases in the heart and ultimately in the lungs via the pulmonary veins. This added pressure in the pulmonary veins results in a leaking of fluid from the bloodstream into the air sacs in the lungs. As the amount of fluid increases in the air sacs, breathing becomes more difficult. In addition, fluid may also back up into the lower legs, causing swelling. With or without fluid accumulation in the air sacs, the buildup of pressure in the pulmonary veins can also cause the lung tissue to lose its suppleness and create the sensation of laboured breathing. Pulmonary dyspnea as a result of lung disease is usually due to the narrowing or stiffening of the airways, which makes it physically difficult to get air in and out of the lungs. People with asthma or emphysema often experience pulmonary dyspnea. This may occur when engaging in movements that prevent the lungs from expanding properly, even simple ones such as bending over or getting dressed up. Distinguishing between cardiac dyspnea and pulmonary dyspnea is not always simple, but people with pulmonary dyspnea, whose lungs have lost their suppleness over a long period of time, tend to breathe more slowly and deeply, especially in moving air out of the lungs. Those with cardiac dyspnea tend to move air in and out of the lungs in short, shallow breaths. Then there is psychological dyspnea which is usually brought on by feelings of anxiety. In this case, breathing tends to be shallow and rapid, causing hyperventilation. This type of dyspnea may be even more dramatic than shortness of breath caused by mild heart failure. The most severe example is the shortness of breath that ensues after a panic attack. The dyspnea usually will go away with exercise or if the person takes slow, deep, controlled breaths or, if the dyspnea is extreme, holds the breath. Psychological dyspnea is often characterized by a sensation of difficulty in getting air in. Even though this is a psychological rather than a cardiac condition it should not be ignored. When panic disorder is diagnosed, it can be successfully treated by a variety of means, including anti-anxiety drugs, talk therapy or both. Other major causes of shortness of breath include pneumothorax, pulmonary embolism, and paroxysmal nocturnal dyspnea. Pneumothorax is a relatively uncommon condition that occurs when air escapes through a leak in one of the air sacs in the lung and when there is buildup in the chest cavity.
