Hair loss (alopecia): causes, patterns and when to see a GP

Hair grows in cycles, and a certain amount falls out every day. The NHS puts normal loss at 50 to 100 hairs a day. What is not normal is a visible change: a widening parting, a receding hairline, hair coming away in handfuls, round bald patches, or thinning all over. The pattern matters more than the quantity.

The NHS says hair loss is not usually anything to worry about, but occasionally it can be a sign of a medical condition, and that it can be upsetting. For many people hair is part of identity, and the NHS says counselling and support groups can help when hair loss causes distress.

The pattern of hair loss is the best clue to its cause. The table brings together the NHS and NICE CKS descriptions.

Hair loss on its own rarely needs urgent attention. The NHS advises seeing a GP if you are worried about it. The signs that make a medical cause more likely are those from the table above: tiredness, weight change, feeling cold or constipated, irregular periods or other changes in menstrual pattern, symptoms of menopause, or signs of anaemia such as breathlessness and paleness.

Sudden patchy loss in a child, loss in a pregnant or breastfeeding person, uncertainty about the diagnosis or failure to respond to treatment in primary care are CKS reasons to refer to a dermatologist. Hair that is lost along with a scaly, inflamed or scarred scalp suggests a condition other than simple thinning, and CKS includes examination of the skin for scarring or inflammation to look for an alternative diagnosis.

• Sudden, patchy hair loss, particularly with nail changes.

• Hair loss with fatigue, weight change, feeling cold, constipation or dry skin.

• Hair loss with irregular periods, acne or excess facial hair.

• Scalp that is red, scaly, painful or scarred.

• Hair loss after starting a new medicine or beginning cancer treatment.

• Significant distress, which the NHS says is itself a reason to talk to a GP.

The NHS says the GP may be able to tell what is causing the hair loss by looking at your hair, and asks you to say if it is affecting your wellbeing. For alopecia areata, CKS lists the questions: how extensive the loss is, whether nails, beard, eyelashes or eyebrows are affected, how it is affecting you psychologically and socially, previous episodes, current and past treatment, family history and personal or family history of atopy or autoimmune disease.

Examination looks at the pattern, the scalp for scarring or inflammation, and the nails. For the diffuse type, a clinician may ask about recent illness, diet, weight loss, medicines, childbirth and menstrual history.

Many people need no tests at all. Where a medical cause is suspected, blood tests can look for an underactive thyroid (TSH and T4, as the NHS describes), anaemia and iron stores, and, when the history suggests it, hormone levels.

CKS emphasises that alopecia areata is diagnosed from its typical clinical features: patchy circular or oval areas of loss, sometimes with short, broken exclamation mark hairs at the edge during active disease.

The NHS says most hair loss needs no treatment because it is temporary and will grow back, or is a normal part of ageing. Hair loss caused by a medical condition usually stops or regrows once the condition is treated. For male pattern baldness the NHS names finasteride and minoxidil, and minoxidil for female pattern baldness; women should not use finasteride. They do not work for everyone, work only while used, and are not all available on the NHS.

For alopecia areata, CKS says options range from no treatment, which is reasonable when hair is regrowing, to specialist referral and a three-month trial of a potent topical corticosteroid in adults. The NHS lists steroid injections or creams, immunotherapy, ultraviolet light treatment, micropigmentation, hair transplants and wigs among other options, some of which are not available on the NHS. For wigs, synthetic ones last 6 to 9 months and real-hair wigs 3 to 4 years, according to the NHS. Alopecia UK offers support groups.

The NHS recommends seeing a GP first. They can look for treatable causes, discuss options and arrange support. A dermatologist is the specialist for patchy or scarring hair loss, uncertain diagnoses and cases that do not respond to first-line treatment, and CKS also lists children and pregnant or breastfeeding people as reasons to refer.

People who want cosmetic treatments such as hair transplants should get the cause clarified first. The NHS says to see a GP for an idea of what is causing the hair loss before thinking about going to a commercial hair clinic.