Thinning or greying locks? Dr Mel Wynne-Jones explains the reasons behind and what you can do to help

We have more than 100,000 hairs on our head and on an average day around 100 fall out. They grow at about half an inch per month until they reach their maximal length, stop, fall out (called the telogen phase) then rest for a few weeks.

Of course, they’re all at different stages so we don’t really notice. However, poor growth and excessive fallout can cause genuine and significant distress. An estimated six million UK women suffer from some form of hair loss, although it’s probably under-reported.

Why do we experience grey hair and thinning hair?

Normal ageing changes

When we start to go grey depends on our genes and environment. The first ‘grey gene’ has already been identified and gene therapy is a future possibility. Men may start losing temple and crown hair from their thirties onwards; this can be treated with minoxidil lotion or anti-hormone finasteride tablets (available on private prescription).

‘Female pattern hair loss’ can be hereditary, and tends to start after the menopause, but sometimes occurs earlier, and may be linked to polycystic ovary syndrome. It causes generalised hair thinning – individual hairs become thinner and shorter as the hair follicles slowly shrink and give up (this can take decades).

Sometimes women develop male pattern hair loss; minoxidil may help but is less effective in women.

Telogen effluvium

This means a sudden, dramatic increase in hair shedding, and commonly occurs after pregnancy when hormone levels (which postpone shedding) fall. TE can also occur as a result of stress, severe illness, poor diet, and some medicines (such as anticoagulants or beta blockers used for heart and blood pressure problems).

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The thinning hair condition can last several months and be very worrying, but although there’s no treatment, your hair should eventually regain its former glory.

Health triggers

Hair follicles need nourishment, and thinning hair can be a sign of iron or zinc deficiency, or a thyroid gland disorder.

You may feel tired, unwell and perhaps also have period problems. You’ll need tests to find out what’s wrong (and why), but supplements or thyroid treatment, if appropriate, will improve hair growth and your general health.

Stress can cause longer-term hair loss, too.

Chemotherapy can make hair fall out, although wearing a ‘cold cap’ may protect follicles. Lost hair may grow back curlier or a different colour.

Scalp problems

Alopecia (hair loss) may be patchy (alopecia areata) or complete (totalis). Body hair may be lost, too (universalis). Alopecia is thought to be an immune-system disorder, and may be linked to patchy skin whitening (vitiligo), diabetes or thyroid problems.

The skin becomes completely smooth and hairless. Adjacent hairs may look like exclamation marks. In four out of five cases, regrowth occurs within a year but severe or extensive alopecia is sometimes permanent. Steroid cream can help. Occasionally steroid tablets, other chemicals or ultraviolet light may be successful.

Scarring alopecia is a rare and difficult-to-treat form, linked to skin conditions including lichen planus or lupus. Fungal infections, such as ringworm, can cause itchy, inflamed patches that can be cured by antifungal creams or prescription tablets.

5 tips for keeping your hair healthy

1. Boost iron and zinc intake by including meat, beans, nuts, dried apricots, watercress, whole grains and shellfish in your diet.

2. Don’t drag hair into styles that can cause traction-alopecia (such as ponytails or cornrows) or use heated rollers.

3. Avoid strong chemicals in dyes/hair products or very hot hairdryer settings.

4. On holiday, protect hair from  sun with a hat, and swimming pools or sea water by rinsing hair with fresh water after swimming or using products designed to protect against sun and salt.

5. Find ways to reduce stress, such as exercise and mindfulness.