There may not be one cause for hair loss in all cases. Instead, there may be many factors that can lead to hair loss. This 13-point checklist will help you determine which causes of hair loss may be applicable to your case. Let's first talk about hair growth cycles. Hair goes through a series of cycles: growth, resting, and shedding. Hair loss is when hairs that have been lost are not replaced or more hair follicles enter the resting phase.…