Hair loss causes
Pattern hair loss and DHT: a plain-English overview
How DHT fits male- and female-pattern thinning — without blaming one hormone for everything.
Male- and female-pattern thinning often runs in families. For many people, DHT (dihydrotestosterone — a hormone made from testosterone) is part of why some follicles grow finer and shorter over the years. Genetics decide who is more sensitive. DHT is not the only story in every case, but it explains a large share of common pattern hair loss without turning it into a single-hormone myth.
What doctors look for on your scalp
Pattern, distribution, and miniaturisation help distinguish androgenetic thinning from diffuse shedding or inflammatory conditions. Photography and follow-up can clarify progression over time.
How DHT ties into pattern thinning
Your body makes DHT from testosterone using the 5α-reductase enzyme. In people whose follicles are genetically more sensitive, that extra DHT exposure is a well-studied reason hairs can grow finer and shorter over years — the familiar temple and crown pattern in men, or wider part / crown thinning in many women. Other shedding causes can still sit on top; this is one major lane, not a single explanation for everyone.
Women get pattern hair loss too
Female-pattern presentations may include widening of the part or diffuse crown thinning. Hormonal conditions can overlap; assessment is not based on a single lab value. For diffuse symptoms, see diffuse thinning in women.
When blood tests help
In selected cases — for example rapid onset, atypical patterns, or symptoms suggesting another cause — clinicians may order blood tests. This does not mean every case of pattern thinning requires extensive laboratories.
Treatment options (big picture)
Prescription options that change androgen pathways or support follicles exist for pattern loss; they need medical supervision and a talk about risks. For how finasteride compares with saw palmetto as categories of treatment, see finasteride vs saw palmetto — education only, not a personal recommendation.
What results usually look like
Care that starts with the right diagnosis usually means shared decisions and patience — think months, not weeks. No medical therapy promises full teenage density back; many people aim first to slow loss, then see how much regrowth they get.
Terms in this article
- DHT (dihydrotestosterone)
An androgen metabolite relevant to androgenetic patterning in susceptible follicles; one factor among many in hair biology.
Related topics
Who wrote this and who checked it
Articles are drafted for patient clarity, then reviewed for medical accuracy under HLI editorial standards. Sources are listed where they help you verify claims; this education still does not replace an exam or plan from your own clinician.
Author
Hair Longevity Institute Editorial
Clinical education
Trichology-led medical writing
Reviewer
HLI Clinical Review
Medical accuracy review
Senior trichology sign-off before publication; same review standard across insight articles.
Frequently asked questions
Should I test DHT blood levels to diagnose pattern hair loss?
Diagnosis is usually clinical. Blood tests may be used in selected scenarios — for example atypical features — not as a routine screen for every case.
If I block DHT, will all my hair come back?
Medical therapies can slow miniaturisation and support regrowth in responders, but results vary. Existing miniaturisation and duration of loss influence outcome.
Is DHT “bad” for the whole body?
DHT has normal physiological roles. Medications that affect DHT are prescribed when potential benefits outweigh risks — a conversation for your clinician.
Can women have androgenetic thinning without high androgens?
Yes. Female-pattern presentations do not always mirror male lab patterns. Assessment stays clinical first.
References & further reading
Related articles
- ConditionsThinning hair in women: common causes and how doctors sort them outMany women notice a wider part, less volume, or more hairs in the brush. This guide walks through common patterns, overlapping causes, when blood tests help, and how to avoid jumping to one internet diagnosis.Read →
- TreatmentsFinasteride vs saw palmetto for hair loss: evidence and important differencesFinasteride is a regulated medicine used for some types of pattern hair loss; saw palmetto is a plant extract sold as a supplement. This article compares how they are studied, regulated, and discussed — not which you should take.Read →
- TreatmentsMinoxidil: how it works and what to expectMinoxidil is a common topical option for some types of pattern hair loss. This article explains the basic idea, why some people shed more at first, how long before you might judge results, and why your diagnosis still guides whether it is appropriate.Read →
- Hair loss causesHair shedding after illness or stress: telogen effluvium explainedTelogen effluvium is a common type of diffuse shedding that can start after you are already feeling better. This article explains typical triggers, timing, how it can overlap with pattern thinning, and when blood tests or a scalp exam matter.Read →
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When to consider blood tests
If shedding is new, severe, or accompanied by systemic symptoms, structured blood review may be appropriate. HLI can help interpret results you already have or suggest what to discuss with your GP.
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