What Is the Norwood Scale?
The Norwood scale, also known as the Hamilton-Norwood classification system, is
a system used by hair loss specialists to determine the stage of male pattern
baldness in a patient. Understanding the Norwood scale is a great way to identify
hair loss in yourself; however, it is highly recommended to speak with an expert for
the most accurate evaluation.
Hamilton-Norwood Scale Background
The Hamilton-Norwood scale was developed by James Hamilton and O’Tar
Norwood. James Hamilton first introduced his classification system in 1951. He
developed it by observing male pattern baldness in over 300 men and used his
findings to outline a common progression of hair loss. O’Tar Norwood then
improved that classification system in 1975. Norwood observed 1,000 males and
determined that Hamilton had left out a few rare patterns in his scale. He added
the Type A variant to the classification system — a similar hair loss progression
with some differences. The combination of Hamilton’s and Norwood’s work led to
the creation of one of the most popular and widely used hair loss classification
The Male Pattern Baldness Stages
The Hamilton-Norwood scale is used to determine the extent of balding,
treatment options and treatment success. The majority of men lose their hair in
common patterns, and the Norwood scale makes it easier to identify which stage a
patient is at in his hair loss. There are seven stages of male hair loss that outline the
beginning stages, from progressive thinning all the way to hair loss in affected
areas. Stage one is no hair loss and seven is considered bald.
Stage 1: There is minimal to no recession of the hairline.
Stage 2: This involves triangular, often symmetrical, areas of recession at the front
of the head near or at the temples. This is often referred to as a “mature” or “adult”
hairline and marks the end of a teenage or adolescent hairline.
Stage 3: The triangular recessions have progressed to the point of being
considered balding. There is little to no hair in these deep recessions, and this is
considered the beginning of the receding hairline stages.
Stage 3 Vertex: This stage is different from the first stages because the hair loss is
beginning at the vertex of the head. There may be slight recession at the front;
however, this type of hair loss primarily begins at the vertex.
Stage 4: In stage 4 of the Hamilton-Norwood scale, we begin to see significantly
more recession at the front of the head and the vertex. There is a rather dense
band of hair separating these two sections.
Stage 5: The front hairline and vertex recession continues to deepen. The band of
hair separating these two sections begins to lessen and balding at the crown
Stage 6: The recession areas have grown more sparse, with the vertex and frontal
areas joining together now. There is also a more noticeable balding crown at this
Stage 7: This is the most progressed stage of hair loss, and only a narrow band of
hair now remains, typically on the sides and back of the head.
These receding hairline stages are very common; however, Norwood observed
another common progression of hair loss. The Type A variant defined by Norwood
is different from the seven stages outlined above in two major ways. First, the hair
loss progresses from front to back with no island developing in the front first.
Secondly, there is no vertex hair loss happening simultaneously.
Frequently Asked Questions About the Hamilton-Norwood Scale
Is Norwood 1 Balding?
The first stage in the Hamilton-Norwood scale, sometimes referred to as Norwood
1, is not balding. This is essentially the control stage in which a male has a full head
of hair with very little to no signs of hair loss.
At Which Stage Do You Recommend Treatment?
The first three stages of the Norwood scale tend to cause a bit of confusion. Since
this scale is a classification system for male pattern baldness, many believe that
every stage is an indicator of hair loss; however, that isn’t quite right. Norwood 1 is
the control stage, where no hair loss is present. Norwood 2 is regarded as the
“mature” hairline stage. What this means is that a man with a Norwood 2 hairline is
simply experiencing the transition from a teenage hairline to an adult one. This
does not indicate hair loss, and treatment is not recommended.
Norwood 3 marks the true beginning of the receding hairline stages. If you meet
the Norwood 3 criteria, hair loss treatment will most likely be recommended.
Treating hair loss early is one of the best ways to slow down the receding hairline
process. If you believe you are starting to lose your hair, request a consultation with
us, and we can evaluate what stage you are at and the best treatment option for