The Norwood scale of pattern baldness indicates the extent of hair loss in androgenetic alopecia affected men

Male and female pattern hair loss information
 Norwood scale for diagnosis of androgenetic alopecia in men

The extent and pattern of male pattern baldness is often classified using a scale. Originally developed by Dr James Hamilton in the 1950s the pattern baldness classification system was modified to its current form by Dr O'Tar Norwood in the 1970s. Dr Norwood's basic scale of pattern baldness is illustrated and described as below.

Type I. The type one pattern indicates minimal hair loss.

Type II. In type two, there are usually limited areas areas of recession of the hair line at the temples.

Type III. Type three is actualy the first level on the scale that a dermatologist would regard as real pattern baldness and something that needs treatment. Most type three scalps have deeper symmetrical recession at the temples. The affected areas are bare or only sparsely covered by hair.

Type III vertex. In this presentation, the hair loss is somewhat different with hairl oss from the vertex (the back of the head) and with only very limited hair line recession.

Type IV. With type four on the scale the hair loss is more extensive than in type three. At this stage there is sparse hair or no hair on the vertex. The hair line recession and the hair loss fro mthe vertex are seperated by a band of moderately dense hair that extends across the top. This band connects with the fully haired fringe on the sides of the scalp.

Type V. With development of type five pattern hair loss, the vertex hair loss region is still seperated from the frontotemporal region but it is less distinct. Here ,the band of surviving hair across the crown is narrower and sparser. The vertex and frontotemporal regions of hair loss are bigger.

Type VI. In type six, the bridge of hair that crossed the crown is now gone with only some sprase hair remaining. The hair line recession and vertex hair loss areas have now joined together and the extent of hair loss is greater.

Type VII. Type seven is the most severe form of hair loss. In people with this most extensive hair loss presentation, only a narrow band of of hair in a horseshoe shaps survives on the sides and back of the scalp. There is little or no hair on the top of the head and the frontal hair line no longer exists.

Norwood scale of hair loss