Diffuse thinning and Norwood recession are two distinct hair loss patterns that require different treatment strategies. Norwood recession follows a predictable pattern of temple and crown loss while the donor area stays stable. Diffuse thinning reduces density across the entire scalp, potentially including the donor area, which changes transplant planning entirely.
The Two Patterns Compared
| Feature | Norwood Recession | Diffuse Thinning |
|---|---|---|
| Pattern | Temple recession, crown bald spot | Uniform density loss everywhere |
| Hairline | Recedes in M or U shape | May remain intact but thin |
| Donor area | Stable, maintains density | May thin (DUPA) or stay stable (DPA) |
| Crown | Distinct bald patch at advanced stages | General thinning, no defined border |
| Scalp visibility | Localized to affected zones | Spread across entire top |
| Transplant candidacy | Generally good | Depends on donor stability |
Understanding the Subtypes
Norwood Pattern (Androgenetic Alopecia, Typical)
The standard Norwood pattern affects specific zones in a predictable order: temples first, then the vertex, then the bridge between them. The donor area on the back and sides remains genetically resistant to DHT, providing a stable supply for transplantation.
This pattern accounts for approximately 80% of male hair loss cases.
Diffuse Patterned Alopecia (DPA)
DPA causes thinning across the top of the scalp in a diffuse manner but preserves the donor area. It can look like Norwood pattern baldness from above but lacks the sharp recession line at the temples. Instead, the density gradually decreases across the entire top.
Key identifier: The donor area maintains normal density (170 to 230 FU/cm2 for Caucasian, 120 to 180 for African, 140 to 200 for Asian).
Transplant candidacy: Good. Since the donor area is stable, DPA patients can undergo transplantation with the same 90 to 95% graft survival as Norwood patients.
Diffuse Unpatterned Alopecia (DUPA)
DUPA is the more challenging variant. It thins the entire scalp including the donor area. Under magnification, the donor zone shows miniaturized hairs mixed with normal ones, a sign that these follicles are also susceptible to DHT.
Key identifier: Reduced density in the donor area, visible miniaturization on dermoscopy.
Transplant candidacy: Poor to moderate. Transplanted grafts from a DUPA donor area may themselves miniaturize and fall out over time, negating the procedure.
How to Identify Your Pattern
Step 1: Examine the Donor Area
The single most important diagnostic step is assessing the back and sides of your head.
- Pull your hair aside at the occipital area (back of head, above the neck)
- Look for miniaturized hairs: Fine, thin, wispy hairs among normal-thickness ones
- Compare density: Does the donor area look as thick as it did 5 years ago?
If the donor area is thinning, you likely have diffuse thinning (possibly DUPA). If it remains thick, you have either Norwood pattern or DPA.
Step 2: Check Your Recession Pattern
| What You See | Likely Pattern |
|---|---|
| Clear M-shape at temples, thick donor | Norwood pattern |
| Temples intact but part line widening | Diffuse thinning (DPA or DUPA) |
| M-shape plus general thinning across top | Norwood + diffuse combo |
| Uniform thinning including sides | DUPA |
Step 3: Professional Confirmation
A dermatologist can confirm your pattern using:
- Dermoscopy: Magnified examination of the scalp and donor area for miniaturization
- Hair pull test: Assessing whether active shedding is occurring across all zones
- Trichogram: Microscopic analysis of plucked hairs to determine growth phase ratios
- Scalp biopsy: Definitive diagnosis if dermoscopy is inconclusive
Treatment Differences
For Norwood Pattern
Standard treatments work predictably:
| Treatment | Expected Result |
|---|---|
| Finasteride 1mg | 80-90% halt loss, 65% regrowth |
| Minoxidil 5% | 40-60% moderate regrowth |
| FUE transplant | 90-95% graft survival, permanent |
| FUT transplant | 90-95% graft survival, permanent |
For DPA (Stable Donor)
Treatment is similar to Norwood, with extra emphasis on medical therapy:
| Treatment | Expected Result |
|---|---|
| Finasteride 1mg | 80-90% halt loss, may improve diffuse thinning |
| Minoxidil 5% | 40-60% moderate regrowth, particularly effective |
| FUE transplant | 90-95% graft survival, good outcomes |
| Dutasteride 0.5mg | Stronger than finasteride for diffuse cases (off-label) |
DPA patients often respond well to minoxidil because the thinning is diffuse rather than total. Miniaturized follicles across a wide area can be revitalized.
For DUPA (Compromised Donor)
Treatment requires caution:
| Treatment | Expected Result |
|---|---|
| Finasteride 1mg | Critical, protects both recipient and donor hair |
| Minoxidil 5% | Apply to donor area as well as affected zones |
| Hair transplant | High risk, donor grafts may miniaturize over time |
| SMP | Good alternative, no donor dependency |
| Hair system | Immediate coverage without donor risk |
Critical warning: If you have DUPA, a transplant without thorough donor assessment can result in transplanted hairs thinning and falling out within 5 to 10 years, leaving you with depleted donor supply and no lasting result.
The Overlap Cases
Many men have a combination of patterns. You might have Norwood 3 recession at the temples with diffuse thinning across the mid-scalp. This is common and does not automatically mean DUPA. The diagnostic question remains the same: is the donor area stable?
Norwood + DPA
This combination is manageable. Treat the diffuse thinning with medication (finasteride + minoxidil) and address the Norwood recession with transplantation. The donor area supports both approaches.
Norwood + DUPA
This combination requires the most careful planning. Medication is the priority to stabilize both donor and recipient areas. If transplantation is pursued, conservative graft numbers (1,500 to 2,000 maximum) with long-term monitoring are advised.
Get an Accurate Assessment
Distinguishing between these patterns requires examining your hairline position, density distribution, and donor area quality. AI-powered tools can analyze overall density patterns and classify your stage.
Get your free AI Norwood assessment to identify your pattern and understand your options before consulting a specialist.
FAQ
What is the difference between diffuse thinning and Norwood pattern baldness?
Norwood pattern baldness causes localized recession at the temples and crown in a predictable pattern. Diffuse thinning causes uniform density loss across the entire scalp, including the sides and back (donor area). The distinction matters because diffuse thinning can affect donor hair quality, making transplant outcomes less predictable.
Can you get a hair transplant with diffuse thinning?
It depends on the type. Diffuse patterned alopecia (DPA) thins the top but spares the donor area, making transplants viable. Diffuse unpatterned alopecia (DUPA) thins the donor area too, which can lead to transplanted grafts eventually falling out. A thorough donor area assessment is essential before proceeding.
How do I know if I have diffuse thinning or Norwood recession?
Check three things: (1) Is your donor area thinning? If yes, suspect diffuse thinning. (2) Do you have defined recession at the temples? If yes, that is Norwood pattern. (3) Is thinning uniform across all zones or concentrated at the hairline and crown? Uniform thinning points to diffuse, while zone-specific loss points to Norwood. A dermatologist can confirm with a dermoscopy exam.