Gray hair is a common sign of aging. It occurs when the pigment cells in the hair follicles stop producing melanin, the pigment that gives hair its color. The exact age at which gray hair starts to appear varies from person to person, but it typically begins in the late 30s or early 40s. However, some people may start to get gray hair as early as their 20s, while others may not get any gray hair until their 50s or 60s.
There are several factors that can contribute to the development of gray hair, including genetics, hormones, and lifestyle factors such as smoking and stress. While there is no surefire way to prevent gray hair, there are some things that you can do to slow down the process, such as eating a healthy diet, getting regular exercise, and managing stress.