The Norwood Baldness Scale
The Norwood scale is used to guage and describe the extent of male pattern baldness. It ranges from types or stage 1 through stage 7. The scale was first introduced by Dr. James Hamilton in the 1950s and revised by Dr. Norwood in the 1970s.
| Norwood Type 1 | No apparent scalp hair loss or recession. Most men around age 16 will display this type of hair. |
| Norwood Type 2 | Minimal recession in the temple area up to several centimeters. May also have slight thinning of the vertex (crown) area. Most would not be considered to be losing their hair. |
| Norwood Type 3 | Moderate recession in the temple area reaching as far back as the middle ear if viewed from above. More pronounced thinning of the vertex but not enough to notice in normal lighting. |
| Norwood Type 3 Vertex | Same as Nowood 3 but with more aggressive thinning of the vertex of the scalp. |
| Norwood Type 4 | The front center portion of the scalp has recessed several centimeters. The vertex has thinned enough to be very noticeable in normal lighting. |
| Norwood Type 5 | The front portion has receded significantly more with only a small amount of viable hair left in the region. The center of vertex area may be completely hairless and the entire vertex thinning area is much larger. |
| Norwood Type 6 | The frontal recession has begun to meet the vertex thinning. Little viable hair is left in the frontal region. The center vertex hairless region is large and pronounced. |
| Norwood Type 7 | The final stage of male pattern baldness. Most hair on the front and top of the head is gone. The hair that remains if any is small and light. The scalp is normally shiny and hairless. |
| Diffuse Thinning | A rare type of hair loss that some men suffer from is consistent thinning over the entire scalp. This is called diffuse thinning or female pattern baldness. This type of thinning is not shown on the Norwood scale. |