Hair Health . Symptoms guide
Diffuse Hair Thinning All Over: What to Rule Out First
Quick answer
When hair is thinning evenly across the whole scalp rather than in a specific pattern, the most likely causes are nutritional, thyroid or a recent reactive trigger (telogen effluvium). Androgenetic alopecia also has a diffuse component in women. A comprehensive blood panel is the fastest way to confirm or rule out the metabolic and nutritional deficits that trigger or worsen this type of thinning.
This patient information is being clinically reviewed by our team. The factual content draws on UK guidance (NHS, NICE, British Association of Dermatologists, and other specialist society guidance where cited).
What this might be
- Iron deficiency. Most common single reversible cause.
- Thyroid dysfunction. Both hypo and hyperthyroid present this way.
- Vitamin D, B12, zinc deficiency. All contribute to disrupted cycling.
- Telogen effluvium. Reactive shed; often lags the trigger by months.
- Diffuse androgenetic alopecia. Less common pattern; a hormone and DHT panel screens for androgen excess that may be aggravating the genetic component, rather than diagnosing the genetic process itself.
Common features that suggest this
- Hair feels thinner overall, not just in one spot
- Reduced ponytail thickness
- Brittle nails or fatigue
- No sudden trigger but slow change over many months (in contrast to acute, high-volume shedding which usually has a clear inciting event a few months earlier)
Recommended tests
Same-day appointments at our Harley Street clinic, results clinician-reviewed.
Need a marker not in these panels? Build a custom panel and a GMC-registered clinician will design one for you.
Markers your clinician will commonly look at
These are the individual blood markers in the recommended panels above. Click any to read what it measures, its UK reference range, and what high or low values mean.
Testing advice
No fasting required. Morning slot recommended if hormones are included.
Common questions
Which panel is most useful for diffuse thinning?
Hair Loss Essentials covers the common nutritional and thyroid causes. The Advanced Hair and Hormone Check adds DHT, androgens and oestrogen, which becomes important if Essentials results return normal.