For many people, hair is synonymous with beauty, and unexpected hair loss can trigger worry and concern. You may be alarmed by the amount of hair that falls out after you run your fingers through your mane, but this small amount of hair loss usually warrants no concern -- as some shedding is a normal part of the hair's life cycle. If abnormal hair loss occurs, it may be caused by styling habits or signal a health issue that needs to be addressed with your doctor.
Hair Life Cycle
Hair grows in cycles. Most hair is in the anagen, or growing phase, which lasts 2 to 8 years. After growth stops, the transitional catogen stage briefly occurs. At any given time, about 5 to 10 percent of hair is in the third, or telogen stage -- the final resting phase which lasts 2 to 3 months. At the end of this telogen stage, old hair is pushed out of the follicle as new growth starts. This is when hair can easily fall out or shed. Humans usually shed as many as 100 hairs each day during the telogen phase, and this hair loss is most noticed when washing or brushing hair, or when running fingers through it.
Styling Habits and Treatments
Sometimes abnormal hair loss is caused by aggressive styling or harsh treatments, and when you run your fingers through your hair, excessive hair falls out. Traction alopecia is a form of hair loss triggered by ongoing stress to the hair. This loss is caused by styles that pull the hair too tightly for extended time periods, such as tight braids, weaves, cornrows or the frequent use of curlers. Harsh chemicals and heat treatment can also lead to this form of hair loss. Most often, eliminating the pulling or the stress to the hair will allow the hair to regrow.
Abnormal shedding of hair, most noticed when hair is brushed, styled or washed, may also be caused by a condition called telogen effluvium. This occurs after a major stress to the body, such as a severe illness, rapid weight loss, pregnancy or surgery, and causes an increased number of hairs to enter the telogen phase. Up to 50 percent of body hair can be lost as a result of this condition, according to an August 2009 article in "American Family Physician," which is correctable once the stressor is removed. Chemotherapy or other medications can lead to temporary hair loss as well, and certain medical or autoimmune conditions can cause temporary or permanent hair loss.
Hair shedding is a normal part of the hair growth cycle, and is most noticeable when you wash, brush or handle your hair. If you detect an abnormal amount of hair shedding or loss -- significantly more than 100 strands per day on average -- speak with your doctor about potential causes and solutions.
Reviewed by Kay Peck, MPH RD