Shedding hair is different from hair loss, when a hair falls out and doesn’t grow back. People often shed hair during stressful events, such as childbirth, a breakup or divorce or during times of grief. Aside from heredity, noticeable hair loss can be caused by wide variety of factors, including Harsh hairstyles or treatments, Hormone imbalances, Illness or surgery, Medications and vitamins, Nutritional deficits, Aging etc.