Hamilton-Seven Norwood’s Seven Stages of Development
There are seven stages on the Hamilton-Norwood scale. Each phase represents a different level of severity and pattern of hair loss.
There are no bilateral recessions at the anterior border of the hairline in the frontoparietal areas, indicating a lack of bilateral recessions. There has been no noticeable hair loss or receding of the hairline.
A slight recession of the hairline around the temples may be seen in stage 2 of the process. A similar amount of hair is lost or sparsely distributed along the mid frontal border of the scalp, although the depth of the afflicted area is much less than that seen in the frontoparietal areas. Generally speaking, this is regarded as an adult or mature hairline, depending on who you ask.
During this stage, the first symptoms of substantial balding begin to show. At the temples, there is a deep, symmetrical recession that is only sparingly covered by hair, and this is not uncommon.
Stage 3 Vertex.
The hairline remains in stage 2, despite the fact that there is significant hair loss on the top of the head (the vertex).
Stage 4 is characterized by a more severe hairline recession than stage 2, as well as dispersed hair or no hair on the vertex of the head. In this condition, there are profound frontotemporal recessions that are generally symmetrical and that are either naked or just sparsely covered by hair.
In stage 5, the regions of hair loss are more noticeable than they were in the previous stage. They are still split, but the ring of hair that separates them is thinner and sparser than it was before.
The link of hair that spans the crown is no longer visible, and only scant hair is left on the scalp. Due to the merging of the frontotemporal and vertex regions, the degree of hair loss is greater in these areas.
This is the most severe stage of hair loss, with just a ring of hair remaining around the sides of the head to show for it. This kind of hair is typically not thick and may be rather tiny.
Norwood class A.
This is a somewhat different and less prevalent categorization of hair loss than the previous one. Norwood also established a Type A version of his conventional categorization method, which is characterized by two main traits and two minor features. Type A variants are classified as follows:
1. The hairline transitions from the front to the back without leaving an island of hair in the mid-frontal area.
2. The formation of a bald patch on the vertex does not occur in a synchronized manner. Rather, the frontal hairline recession continues to move to the back of the head as time passes.
1. The region of hair loss is characterized by sparse hair dispersion.
2. The horseshoe-shaped sections of hair that continue on the side and back of the scalp tend to be more widespread and reach higher up on the head than the other areas of hair.