How to measure the health of blood vessels?

Whether the blood vessels are healthy or not can be self-tested by ordinary patients. First of all, patients make preliminary judgments according to their age and other conditions. For example, patients with middle age, too greasy diet, obesity, smoking and alcoholism have a high probability of suffering from vascular diseases. Secondly, patients can observe the veins on the surface of their skin. For example, patients can see whether the superficial part of their skin has a vein protrusion. If the thenar vein is obvious, it means that the lung function is weak and it is easy to catch a cold. If the veins in the temple are obvious, patients are prone to high blood pressure or migraine. In addition, patients can observe their sublingual veins. If the sublingual collaterals are obvious, it means that there is a problem with the patient's body fluid circulation, such as heart disease or stroke.