A normal human being loses 50 to 100 hairs on a daily basis, but it doesn’t make thinning of scalp hair noticeable because new hair is growing in at the same time. Visible hair loss occurs when the cycle of hair shedding and growth is disrupted or when the hair follicle is damaged and scar tissue is formed.
Hair loss can be attributed to four main factors, namely heredity, changes in hormones, medical conditions and finally medication. The hereditary condition known as pattern baldness is the most common reason of hair loss. It occurs gradually and with a receding hairline and bald spots in predictable patterns in men and thinning hair in women. Heredity dictates the age when one begins to shred hair, extent of baldness and finally the rate of hair loss. Among men, pattern baldness is common whereas in women, hair loss occurs in form of thinning of hair.
Hair loss can also be triggered by hormonal changes and imbalances during pregnancy, childbirth, onset of menopause and thyroid problems. Patchy hair loss or alopecia areata occurs when the human body's immune system attacks and damages hair follicles causing hair loss and leaves behind smooth bald patches on the skin. Scalp infection like ringworm leads to scaly patches and hair loss. Skin disorders like lichen planus, sarcoidosis and trichotillomania causes people to have an irresistible urge to pull out their hair, whether it's from the scalp or other areas of the body.
Excessive use of hairstyling tools like iron curlers and products like gels, mousse, sprays and colours damage the hair and prolonged usage can hamper its growth. Hairstyles which pulls one’s hair tight like pigtails or cornrows cause traction alopecia. Hot oil hair treatments cause inflammation of hair follicles leading to hair loss.
Medicated drugs for arthritis, depression, cancer, hypertension and even birth control increase the rate of hair loss. As the hair is made of keratin which is a protein, if one has a protein deficiency, then the chances are that the hair will be brittle. Crash dieting and losing a lot of weight too quickly has an adverse effect on hair growth, because these diets deprives body of essential nutrients which impact hair growth.
Psoriasis and Diabetes responsible for loss of hair. Diabetes affects the body’s circulatory system due to which less amount of nutrients and oxygen reach the feet and the scalp areas due to which the hair follicles get damaged. Psoriasis is a skin disease which affects the scalp and hair follicles leading to red bald patches.
If one notices thinning of hair, it is best to get checked for any underlying condition which could be causing the hair loss. If you wish to discuss about any specific problem, you can consult a Dermatologist.