I came across an article online about misunderstanding and reality regarding "gray hairs" and would like to share it here. You might have an experience that you were shocked by finding out that you were going gray when you checked yourself in the mirror. This kind of change which most people have experienced when they are in their 30s to 40s is a part of aging naturally. The research team in Seoul University hospital says it's highly likely that either one of your parents have the same experience if you started going gray in your 20s. If your parents already had gray hairs when they were young, their children have the risk of 19 times that they will be going gray as well when they are young. It is caused especially by father's genetic affection. The stress blocks blood circulation and makes blood vessels, which provide hair roots with nutrient, constrict. Hence, the stress is one of causes for gray hairs. However, gray hairs never return back to black ones even if you release your stress. There is a rumor that gray hairs increases when you pull ones out. This is not true. Basically, a hair root has one hair. So, some hairs never grow in the hair root after you pull a gray hair. It seems that we need plenty of exercises and rests if you want to prevent your gray hairs from growing as much as possible.