Hardening of the arteries, also called atherosclerosis, occurs when fat, cholesterol, and other substances build up in the walls of arteries. These deposits are called plaques.efinition. Hardening of the arteries, also called atherosclerosis, occurs when fat, cholesterol, and other substances build up in the walls of arteries. These deposits are called plaques. Over time, these plaques can block the arteries and cause problems throughout the body.
CNS fatigue (CNS = central nervous system) is a slightly more convoluted phenomenon, but the term is thrown around frequently in the world of fitness. By itself, the acronym evokes notions of frailty, complication, and extreme caution.NS fatigue (CNS = central nervous system) is a slightly more convoluted phenomenon, but the term is thrown around frequently in the world of fitness. By itself, the acronym evokes notions of frailty, complication, and extreme caution.
3. Chronic fatigue syndrome. Chronic fatigue syndrome (also called myalgic encephalomyelitis or ME) is a severe and disabling tiredness that goes on for at least six months. There are usually other symptoms, such as a sore throat, muscle or joint pain and headache. Read more about chronic fatigue syndrome.