People age all the time, but their appearance does not necessarily keep pace with their age. When the appearance does not match the age and clearly looks older or younger than the actual age, different people will have different explanations for this. Especially if you look older than your actual age, it is often interpreted as premature aging. In fact, many scientific studies support the reasoning that there are actually signs of aging. 　　A long-term follow-up heart study in Copenhagen found that gray hair, facial wrinkles, and male pattern baldness are obvious signs of aging, which may indicate that people are at a higher risk of myocardial infarction, especially those…