Hair Health . Symptoms guide
Diffuse Hair Thinning All Over: What to Rule Out First
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. Bloodwork is the fastest way to identify which one is active.
This patient information is being clinically reviewed by our team. The factual content draws on UK guidance (NHS, NICE, British Association of Dermatologists, British Society for Sexual Medicine 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; needs hormone and DHT review.
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
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.
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.