Red flag symptoms
- Complete hair loss
- Sudden hair loss
- No apparent external cause
- Excessive unexplained tiredness
- Weight loss
- Suspected kerion
The most common type of hair loss is a gradual thinning, starting at the top of the head. Hair growth and loss can be affected by:
- Hormonal factors such as pregnancy, childbirth, menopause, polycystic ovaries and thyroid problems.
- Medications, for example for cancer, arthritis, contraception, depression, diabetes, heart problems, hypertension and gout.
- Medical conditions including diabetes and autoimmune diseases, for example, hyperthyroidism.
As well as prescribed medication, consider accidental or deliberate poisoning. Anaemia or excessive weight loss can be relevant if there is a lack of iron, protein, zinc, fatty acids or vitamins.
Hair loss can happen gradually or suddenly. It may recover or remain permanent.
Localised hair loss (alopecia areata) is likely to be an autoimmune process, which can cause scalp itchiness, redness and tenderness. Local fungal infection can create a similar pattern as alopecia areata.
Traction alopecia is a mechanical issue, when hair styling – ponytails, braids – pulls the hair frequently and too hard. Hot oil hair treatments and some colouring or hair dyes may also cause inflammation of the hair follicles, which can lead to scarring and subsequent permanent hair loss.
A sudden loosening of hair through an emotional or physical shock typically becomes apparent several months after the event and usually results in handfuls of hair coming out. It tends to cause general thinning of the hair overall, rather than any bald patches. Hair often recovers again, but possibly not fully.
Sometimes habitual tugging, pulling and plucking (trichotillomania) of hair can be an expression of psychological distress, occasionally even with a denial that it is happening.
- Tinea capitis
- Alopecia areata
- Lichen planus
- Medication side-effects
- Trauma and 'shock fallout'
History and examination
Establish the time-line of observed hair loss and the quantity and distribution of it. Check medication changes, stresses or any physical impacts. Be mindful of universal red flags, such as unexpected weight loss, behaviour change or metabolic changes.
Look out for any apparent irritation, scarring or a kerion (a thickened, inflamed, pus-filled area over the scalp). This is a complication in severe tinea capitis.
Kerion is a dermatological emergency. Only prompt treatment with systemic steroids will prevent the destruction of the hair follicles and inevitable permanent hair loss.
Consider some baseline investigations including FBC, U&E, LFTs, TFT, ferritin, HbA1c and inflammatory markers.
Unless there is a clear reversible cause for the hair loss, the treatment options are often limited. Referral for a second opinion may be useful to confirm the diagnosis and to further inform cosmetic management options.
Commercial products such as tonics or supplements and surgical options including hair transplants are, in many cases, very expensive and may not achieve the desired results.
- Dr Tillmann Jacobi is a GP in York. This article first appeared on 10 April 2009 and was updated by the author in June 2019.