How many hair loss grades are there?

Hair loss can generally be divided into seven grades, a normal hair line, hair line after the second class hair loss, forehead slightly higher. Grade three hair loss hair line loss is obvious, need to actively take hair transplant treatment. Grade four hair loss forehead obviously bald, head part of hair thinning. Grade five hair loss forehead and head rotation part of the overall loss, hair loss area is larger. Grade six hair loss forehead part of hair loss basic loss, head top backward expansion is more obvious. Grade 7 alopecia, hair is generally only left behind the occipital and ear temples around a circle of hair.