Each day an average of 30-100 hairs fall out as part of the normal growth cycle. These are hairs that are in the last stage of growth cycle. Shedding occurs because there is a new hair (anagen) beginning to grow which pushes the older inactive hair (telogen hair) out of the follicle. There is a seasonal variation in hair growth, with increased loss in the spring, late summer, and early fall (August and September).
Hair loss or alopecia is defined as a decrease in density of hair. This can be due to a number of factors. Genetics, autoimmune diseases that may be systemic or just localized to the scalp, endocrine disorders, nutritional deficiencies, infection, trauma to the hair shaft, hormonal imbalances, medications, biologic or psychological stress, surgery, and other medical illnesses can cause hair loss.
The following information is useful when you are coming to be seen for a hair problem.
Diagnosing the cause of alopecia may involve a scalp biopsy. This involves anesthetizing an area and taking a small sample of tissue for examination under the microscope by a dermatopathologist.
Sunlight damages the amino acids in the hair cuticle. Hair can be more brittle, stiffer, and drier as a consequence. Breakdown of cystine, a major amino acid in hair results in a gradual loss of structural integrity. Wearing a hat when outdoors can prevent photodegradation of hair protein.
Cigarette smoke associated hair loss has an androgenetic pattern. Smoking induces oxidative stress to hair follicles causing them to release inflammatory proteins called cytokines. The microinflammation around hair follicles inhibit their growth. Comb hair gently to minimize friction between hair and the comb. The comb or brush should have widely spaced teeth preferably Teflon coated with ball tips. Combing friction is maximal when hair is tangles. Avoid teasing hair as this contributes to breakage. Teasing is a styling technique whereby hair is back combed to create the illusion of volume. This is damaging to the hair shaft and causes breakage. Conditioners improve manageability of hair by decreasing static electricity and friction during grooming. Do not style hair until it is almost dry. Gently detangle hair after shampooing from the ends and then work up with fingers.