Hair loss in women generally begins at menopause, because until then the DHT hormone in women is counteracted by estrogen. The estrogen levels in women drop at menopause, leaving hair follicles open to the effects of DHT. Hair loss in women is observed by marked thinning of hair across the scalp, very unlike men. It is very rare to see complete bald spots at the crown in women.
Another common cause of hair loss in women is traction. Traction is caused by prolonged or excessive pulling on the hair follicles. This type of balding is commonly caused by hairstyles like braiding or pony tails.
Female Baldness: The Savin Scale
Currently there are 4 different scales with which to measure hair loss in women, created by different doctors (Ludwig scale, Olsen scale, Ebling-Roock scale, and Savin scale). Of these, the Savin scale is the most popular due to its details as a method to measure hair loss in women.
The first image (class 1) shows an image of a woman without hair loss. Images 2 - 4 (marked as classes 2, 3, and 4) indicate a progressive loss of hair along the midline of the scalp. Classes 5 and 6 show a diffuse and extensive hair loss but with a bit of hair surviving in these areas.
The image marked as complete represents a woman with extensive hair loss and little or no hair in the area affected by alopecia. Very few women reach this degree of baldness, and if they do so it is because they have some organic cause which justifies it, generally an excessive production of androgenetic hormones.