Hair Classification

The Norwood Classification

A system of hair loss classification is useful in helping doctors compare one patient with another. The Norwood Classification is the one commonly used for male pattern baldness. There are two basic patterns, the most common of which is where hair loss starts in two different areas – the temples and the crown. Less commonly the loss progresses from front to back. Non-genetic hair loss from other causes follows a different pattern:


Hair Classification

Type I

No recession
“Adolescent” hairline

Type II

Temporal recession less than 2.5cm
Mild recession along frontal hairline
“Mature” hairline

Type III

Further frontal hairline recession
Deeper recession at corners, “zipper” opening
Primary stage of balding

Type III Vertex

Hairloss predominantly in vertex (crown)
Frontal hairline recession may be present

Type IV

Further frontal hair loss and temporal recession
Enlargement of crown (bald spot)
Solid band of hair across top separating the frontal area from the crown

Type V

Frontal and temporal balding areas enlarge even further
Band separating the two areas becomes narrower and less dense

Type VI

Frontal and crown balding areas merge into one and increase in size

Type VII

Only a narrow horseshoe band of hair remaining
Low hairline in the back
Hair in permanent zone may be sparse

Type A Variant

Frontal hairline recession keeps advancing backwards
Single area of balding
Eventual extent of balding tends to be more limited than in regular Norwood classes

Type IIa

Entire frontal hairline recedes

Type IIIa

Frontal hair loss extends to the mid scalp

Type IVa

Hair loss moves past mid scalp area

Type Va

Hair loss extends towards the crown
Back part of the bald area is narrower
than in the regular Norwood VI