Hamilton–Norwood Scale
The Hamilton–Norwood Scale is important in the assessment of degree of androgenetic alopecia or pattern baldness for hair transplantation treatment.
Male androgenetic alopecia (AGA) or male pattern baldness can be measured using the Norwood-Hamilton scale which is divided into 7 stages. Before hair transplantation, the surgeon will determine the degree of hair loss using this scale, then use it to estimate the number of grafts required for hair transplantation. It can also be used to predict the cost of hair transplantation and progression of hair loss.
Norwood Scale, Stage 1
At stage 1, Hair loss does not affect or hardly affects the hair on the head. However, there may be slight recession at the hairline corners and M-shaped hairline may develop.
Treatment for hair loss at stage 1 usually requires at least 800 grafts. These hair grafts are typically taken from an area that is not affected by hormones or genetics.
Norwood Scale, Stage 2
At stage 2, there is a receding hairline. The receding hairline ends before the imaginary line drawn across the head (about 2 centimeters above the front of the ear). In addition, the hair at the front of the hairline may be slightly thinner.
At least 1,400 hair grafts are required to cover hair loss at stage 2. These hair grafts are typically taken from the back of the head, an area that is not affected by hormones.
Norwood Scale, Stage 3
At stage 3, hair loss is observed above the imaginary line drawn across the head 2 cm above the ears, and receding hairline may also observed.
At least 2,250 hair grafts are required to cover hair loss at stage 3. These hair grafts are typically taken from the back of the head, an area that is not affected by hormones.
Norwood Scale, Stage 3 Vertex
The hair on the vertex or crown of patients at this stage will become thinner or more shedding in addition to the receding of the hairline.
The number of hair grafts required to cover this degree of hair loss depends on the desired outcome. Generally, 2,500–3,500 hair grafts are required if a density of approximately 30 grafts per square centimeter is required.
Norwood Scale, Stage 4
At stage 4, the retraction and shedding of hair along the hairline is so intensified and only a narrow band is left between the front of the head where the hair falls out from the crown area due to the advanced hair loss.
At least 3,500 hair grafts are required to cover hair loss at stage 4. These hair grafts are typically taken from the back of the head, an area that is not affected by hormones.
Norwood Scale, Stage 5
At stage 5, only a small amount of hair is left at the hair band.
At least 4,000 hair grafts are required to cover hair loss at stage 5. These hair grafts are typically taken from the back of the head, an area that is not affected by hormones.
Norwood Scale, Stage 6 and 7
At stage 6 and 7, there are no hair left on the top of the head, both in front and on the sides of the temples. At this stage, the crown is clearly visible and very little hair is left.
At least 5,000 hair grafts are required to cover hair loss at stage 6 and 7. These hair grafts are typically taken from the back of the head, an area that is not affected by hormones.
At what stage of Norwood scale you should seek treatment?
There is no fixed criterion as to what stage of Norwood scale a patient should make a decision to undergo treatment. Patients should treat their hair loss as soon as possible when signs of receding hairline or thinning hair are noticeable. The sooner hair loss is prevented, the more effective the method is to stop it and the natural hair can be preserved if medical treatments are started early by using medications such as finasteride or minoxidil. The more severe hair loss, the more difficult it is to treat. Before undergoing hair transplantation, most patients have a Norwood scale at stage 4.
Hair Loss Treatments
ธhe progression of hair loss can be effectively stopped by using minoxidil and finasteride. Finasteride inhibits the enzyme 5a-reductase, thereby blocking the conversion of testosterone to dihydrotestosterone (DHT), a hormone responsible for decrease in the growth phase of the hair follicles and hair loss.
The treatment for male pattern baldness using minoxidil is done by applying the product to the scalp, which is claimed by the manufacturer to be able to stop hair loss in 70-80% of patients and can stimulate and increase new hair growth and hair diameter in 30% of patients. Minoxidil is effective when used regularly and the result is first visible after 3-4 months, and is most effective after 12 months.
