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Arteriosclerosis occurs when the blood vessels that carry oxygen and nutrients from your heart to the rest of your body (arteries) become thick and stiff — sometimes restricting blood flow to your organs and tissues. Healthy arteries are flexible and elastic, but over time, the walls in your arteries can harden, a condition commonly called Read more…

Acute respiratory distress syndrome (ARDS) occurs when fluid builds up in the tiny, elastic air sacs (alveoli) in your lungs. More fluid in your lungs means less oxygen can reach your bloodstream. This deprives your organs of the oxygen they need to function. ARDS typically occurs in people who are already critically ill or who Read more…

Appendicitis is an inflammation of the appendix, a finger-shaped pouch that projects from your colon on the lower right side of your abdomen. The appendix doesn’t seem to have a specific purpose. Appendicitis causes pain in your lower right abdomen. However, in most people, pain begins around the navel and then moves. As inflammation worsens, Read more…

Aplastic anemia is a condition that occurs when your body stops producing enough new blood cells. Aplastic anemia leaves you feeling fatigued and with a higher risk of infections and uncontrolled bleeding. A rare and serious condition, aplastic anemia can develop at any age. Aplastic anemia may occur suddenly, or it can occur slowly and Read more…

Aphasia is a condition that robs you of the ability to communicate. It can affect your ability to speak, write and understand language, both verbal and written. Aphasia typically occurs suddenly after a stroke or a head injury. But it can also come on gradually from a slow-growing brain tumor or a disease that causes Read more…

Aortic valve stenosis — or aortic stenosis — occurs when the heart’s aortic valve narrows. This narrowing prevents the valve from opening fully, which obstructs blood flow from your heart into your aorta and onward to the rest of your body. When the aortic valve is obstructed, your heart needs to work harder to pump Read more…

Aortic valve regurgitation — or aortic regurgitation — is a condition that occurs when your heart’s aortic valve doesn’t close tightly. Aortic valve regurgitation allows some of the blood that was just pumped out of your heart’s main pumping chamber (left ventricle) to leak back into it. The leakage may prevent your heart from efficiently Read more…

Aortic valve disease is a condition in which the valve between the main pumping chamber of your heart (left ventricle) and the main artery to your body (aorta) doesn’t work properly. Aortic valve disease sometimes may be a condition present at birth (congenital heart disease), or it may result from other causes. Types of aortic Read more…