Patient guide
Hair loss: main types, tests and when to see a doctor
Hair loss has many causes, from inherited pattern thinning to temporary shedding after illness, autoimmune patches and scarring conditions that permanently destroy follicles. Getting the type right matters because treatments differ and some forms need early treatment. This guide helps you understand the types and what to ask a doctor.
Last checked: 2026-10-03
Key facts
At a glance.
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Different causes
Patterned loss, shedding, patchy autoimmune loss, scarring loss, traction and hair-pulling each have different management.
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Shedding often recovers
Diffuse shedding after illness, stress, childbirth or rapid weight loss usually recovers over months once the trigger resolves.
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Scarring is urgent
Scarring alopecias destroy follicles, so early specialist assessment matters to limit permanent loss.
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Tests are targeted
Blood tests are chosen by pattern and history, not as a standard panel for everyone.
Common types
| Type | Typical features | Outlook |
|---|---|---|
| Androgenetic alopecia | Gradual thinning at temples and crown in men; diffuse thinning over the crown in women; inherited tendency | Progressive; treatments can slow or partly reverse in some |
| Telogen effluvium | Sudden diffuse shedding two to three months after a trigger such as illness, surgery, childbirth, crash dieting | Usually recovers when trigger resolves |
| Alopecia areata | Round or oval smooth bald patches; sometimes nail pitting | Unpredictable; may regrow, recur or progress |
| Scarring (cicatricial) alopecia | Patches with redness, scaling, burning or loss of follicle openings | Permanent loss unless treated early |
| Traction alopecia | Loss at hairline or areas under tension from tight styles | Reversible early; permanent if prolonged |
| Trichotillomania | Irregular broken hairs from pulling | Responds to psychological therapies |
Why the history matters
A doctor will ask when the loss began, whether it is sudden or gradual, whether you have had illness, surgery, childbirth, new medicines, dietary restriction or stress, family history, hair care practices and symptoms such as itching or burning. They will look at the scalp, hair pull test and pattern of loss, and may use a dermatoscope. Photographs over time help.
Tests that may be useful
Depending on the picture, clinicians may check blood count, ferritin and iron status, thyroid function, vitamin B12 and sometimes vitamin D, and hormone tests in women with signs of excess androgens or irregular periods. Skin scrapings or a biopsy are used when infection or scarring is suspected. Broad panels not guided by history often produce incidental results that are not helpful.
Signs that need prompt review
See a doctor soon if loss is sudden and patchy, if the scalp is red, scaly, painful or itchy, if there is pus or crusting, if you notice loss of eyebrows or eyelashes along with scalp hair, or if loss follows a new medicine. In children, any unexplained hair loss deserves assessment. In women, unexplained loss with irregular periods and excess hair growth may point to a hormonal condition.
Treatments in outline
Treatment depends on the cause. Minoxidil and, for men, finasteride are used for pattern loss. Alopecia areata may be treated with steroid injections or creams and, in severe cases, specialist medicines. Shedding often needs only time and treatment of the trigger. Scarring conditions are treated with anti-inflammatory medicines. Cosmetic options include wigs, hair fibres and, for some, transplant surgery.
Emotional impact
Hair loss can affect confidence and mood. Support groups and counselling help, and charities provide advice on wigs and cosmetic camouflage. If hair loss is causing significant distress, tell your GP, because psychological support is part of good care.
Frequently asked
Questions people ask.
Quick, plain-English answers to the questions we hear most.
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Is hair loss after Covid or illness permanent?
Usually not. Shedding after illness often recovers over several months.
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Do I need blood tests?
Often some basic tests are sensible, but they should be guided by your history and examination.
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Can stress cause hair loss?
Severe stress can trigger shedding, typically a few months later.
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Is hair loss hereditary?
Pattern hair loss has a strong inherited component, from either side of the family.
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Does shampoo cause hair loss?
Normal shampoos do not usually cause loss. Some hair treatments and tight styles can damage hair.
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What is a hair pull test?
A gentle test where a clinician pulls a small group of hairs to see how many come out easily.
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Can women be prescribed finasteride?
It is not licensed for women and is not used in women who could become pregnant. Specialists may consider it in specific cases.
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Where can I get support?
Charities such as Alopecia UK and patient groups offer information and peer support.
Where this comes from
Sources and checking.
This guide is for information, not medical advice.
Your GP or consultant knows your history and can tell you which parts apply to you. If your symptoms are severe, rapidly worsening, or come with red-flag features, seek urgent medical care. Figures and availability change, so treat them as a guide and confirm with the provider.
Published 2026-10-03, next review 2027-10-03.
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NHS website, Hair loss pages (nhs.uk)
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British Association of Dermatologists, patient information leaflets (bad.org.uk)
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MHRA drug safety updates and Yellow Card scheme information (gov.uk/mhra)
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General Medical Council, Good practice in prescribing and managing medicines and devices (gmc-uk.org)