The Hamilton-Norwood scale was created to show the progression of male-pattern baldness, it’s an accepted standard scale. It was developed by James Hamilton in the 1950s and revised by O’Tar Norwood in the 1970s.
What is the Purpose of the Norwood Scale?
Even though it is not fully accurate, the Norwood Scale is employed throughout the world for two reasons:
This scale gives a visual tool for patients and doctors to use when describing male pattern hair loss (MPH). From the doctor’s perspective, it is a way to demonstrate to the patient what they can potentially expect to happen next. For the patient, this scale is an easy way to describe their MPH over the phone and during initial consultations.
When studying MPH, the Norwood Scale gives researchers a basic set of like terms to use. It is also easier to describe the earlier and later stages of hair loss using the Norwood Scale numerological phrasing. All in all, the Norwood Scale terminology helps minimise confusion.
Here is each stage of the Hamilton-Norwood Scale:
Type 1 – Minimal hair loss – There is very minor or no recession of the hair line. Unless you have a family history of baldness there is no need to worry. If not, monitor your hair closely.
Type 2 – Insignificant hair loss at the temples – There is triangular/symmetrical loss at the front temporal area. Hair falls and may become less dense in the central front part of the scalp. Initial signs of baldness are becoming evident.
Type 3 – Most scalps at this stage have deep symmetrical recession showing at the temples that are bare or only sparsely covered by hair.
Type 3 Vertex – The crown is added since it’s a common occurrence with age. Hair loss is primarily from the vertex with limited recession of the front temporal hairline.
Type 4 – Bigger pattern on the upper surface and hairline – That baldness at the front temporal areas are more severe than stage 3. A band of hair will usually separate the hair loss between the temporal and crown.
Type 5 – Patterns at both sides are bigger but a thin division line is still present – As the band across the top of the head gets thinner, hair loss on the temporal and crown areas get bigger.
Type 6 – The bridge of hair at the top of the head is now lost with only sparse hair remaining. Then the hair on the sides of the head is staring to fall.
Type 7 - This is the most advanced or severe form of hair loss. Only a narrow band of hair in a horseshoe shape survives on the sides and back of the scalp. This hair may be fine and less dense than before. At the nape of the neck the hair is sparse with a semi-circle over both ears.