The heart muscle is most afraid of ischemia, and with ischemia comes hypoxia. Decreased cardiac blood output is mainly the result of changes in the substances contained in the blood and pathological changes in the lumen of the blood vessels. Most of them are caused by hyperlipidemia and hypercholesterolemia, which are the result of life factors such as unreasonable diet and low exercise. Cholesterol in the blood is divided into high-density lipoprotein cholesterol (high-density alcohol) and low-density lipoprotein cholesterol (low-density alcohol). Low-density alcohols in the blood, in addition to supplying the needs of cells, the excess ones are deposited in the inner walls of arteries, causing the inner walls of blood vessels to start from unsmooth changes until atheromatous plaques are formed, causing the vascular channels to become narrow or even blocked. Therefore, low-density alcohols are injurious cholesterol. In contrast, high-density alcohols bring cholesterol in the blood to the liver, convert it, and then excrete it from the body via the gallbladder into the intestines, which is protective cholesterol. In addition, there are high age, high blood pressure, diabetes, obesity, mood swings, tobacco and alcohol addiction, and adverse reactions to certain drugs that can cause vascular changes resulting in myocardial ischemia and intravascular thrombosis. Cardiovascular disease caused by a decrease in cardiac blood displacement, in the early stage of the onset of the disease is often asymptomatic, gradually appear shortness of breath, shortness of breath, originally up three or four floors without much feeling, now just up to the second floor appears panic, shortness of breath, heartbeat accelerated, indicating insufficient blood supply to the heart muscle, the heart function is weakened, this will be an early indication of cardiovascular disease. If you feel weak and fatigue, chest pain, it is already a more obvious symptom of cardiovascular disease.