Shortness of breath is the feeling of labored breathing or the inability to take in enough air--or more accurately, oxygen. As air enters the lungs through the bronchial tubes, oxygen is exchanged into the blood through the aveoli--tiny air sacs. Once in the blood, oxygen attaches to red blood cells, is carried to the heart and then pumped to all the cells in the body. Any conditions which affect the ability of the lungs to function, the red blood cells to carry oxygen or the heart to pump blood can cause shortness of breath.
Heart Conditions
The heart functions as the motor of the body pumping blood through the complex system of blood vessels. Blood carries vital oxygen and nutrients to cells while picking up waste products for removal from the body. Any condition that restricts the flow of oxygen to the body causes shortness of breath.
Coronary artery disease, the most common form of heart disease according to the National Heart Lung and Blood Institute, is the leading cause of death among men and women in the United States. The buildup of plaque, a sticky substance consisting of fat, cholesterol and minerals, on the blood vessel walls inhibit the flow of blood therefore decreases the level of oxygen available to the cells.
Heart failure occurs when the heart is unable to meet the needs of the organs in the body. A variety of conditions, including coronary artery disease, heart attack, high blood pressure, defective heart valve or an infection within the heart can lead to heart failure. Arrhythmias, or abnormal heartbeats, also cause shortness of breath.
Lung Diseases
The lungs function to perform respiration, the process by which the lungs inhale and exhale to exchange oxygen and carbon dioxide. Any condition or disease that affects the lungs inhibits the exchange of oxygen, which can cause shortness of breath.
Asthma, a condition that affects approximately 23 million Americans according to the American Lung Association, causes increased mucus production and inflammation of the bronchial tubes in the lungs. The inflammation triggers shortness of breath and can become serious if not treated.
Chronic obstructive pulmonary disease, the fourth leading cause of death in the United States as reported by the American Lung Association, is a progressive disease. Damage to the aveoli inhibits the exchange of oxygen resulting in shortness of breath.
Blood Disorders
The blood contains white blood cells responsible for immunity, platelets responsible for clotting and red blood cells responsible for carrying oxygen. Any blood disorder that interferes with the production of red blood cells, the level of red blood cells or their ability to function can cause shortness of breath.
Anemia, a condition characterized by a low red blood cell count, decreases the amount of oxygen delivered to the cells. This causes shortness of breath and fatigue. Sickle cell anemia, a genetic disease prominent in African-Americans, according to the National Heart Lung and Blood Institute, affects the shape of red blood cells causing them to be sticky. This inhibits the flow of blood leading to decreased flow of oxygen in the lungs, heart and to the cells therefore causing shortness of breath.
