From which point is hair root depth measured?

Hair root depth is measured from the uppermost part of the epidermis. This measurement is crucial in electrology, as it helps professionals determine the appropriate depth at which to target the hair for effective treatment while avoiding damage to surrounding tissues. The epidermis is the outer layer of the skin, and understanding this specific point aids in pinpointing the hair's position relative to the skin surface.

The bulb is located deeper within the follicle and is important in understanding the hair growth cycle, but it is not the starting point for measuring root depth specifically for treatment purposes. Similarly, while the follicle itself is essential for hair growth, it does not serve as the reference point for measuring from the skin's surface. The epidermis itself can also refer to a more generalized skin layer rather than pinpointing the exact point of measurement. Thus, the uppermost part of the epidermis is the best and most accurate reference for measuring hair root depth.