Hair loss in teenagers: causes and when to see a doctor

Teenagers worry about their appearance, so noticing hair fall or thinning at 14 or 17 can be upsetting. Some shedding every day is normal at any age. But when hair loss is clearly more than usual, there is often an identifiable cause, and many of the causes in teenagers can be treated or settle by themselves.

Normal shedding versus a real problem

Everyone loses some hair each day as part of the normal hair cycle. It becomes worth looking into when:

• Hair is coming out in clumps or noticeably more than before
• There are smooth bald patches
• The scalp is itchy, scaly, red or sore
• The hairline, crown or parting is gradually getting thinner
• Hairs are broken off at different lengths

Common causes in teenagers

Patchy hair loss (alopecia areata)

Alopecia areata usually causes round, smooth bald patches, and it often starts in childhood or the teenage years. It happens when the immune system attacks the hair follicles. Hair often grows back, but the condition can come and go ¹. Read our alopecia areata explainer.

Scalp ringworm (tinea capitis)

This fungal infection is most common in children. It can cause scaly patches, broken hairs and sometimes tender swelling. It needs antifungal tablets from a doctor, because creams alone do not reach deep enough into the hair follicle ². See scalp ringworm.

Shedding after illness, stress or dieting

A high fever, a serious illness, an operation, crash dieting or a very stressful period can trigger telogen effluvium, a diffuse shedding that usually starts two to four months later and settles within about six months ³. Exam stress and strict diets are worth considering in teenagers. See hair loss after weight loss.

Low iron and poor diet

Heavy periods, vegetarian diets without careful planning, and skipping meals can all lead to low iron. A balanced diet with enough protein, iron and other nutrients supports healthy hair ⁴. See anaemia and hair loss.

Hair pulling (trichotillomania)

Some teenagers pull out their hair, often without fully noticing, as a way of coping with stress, boredom or anxiety. It often starts in late childhood or the early teens ⁵. Patches tend to have hairs broken at different lengths. It is not a sign of bad behaviour, and support is available. See trichotillomania.

Tight hairstyles and styling

Tight ponytails, braids, buns and tight headwear worn every day can cause traction alopecia along the hairline. Frequent bleaching, straightening and heat can cause breakage ⁶. See traction alopecia.

Early pattern hair loss

Pattern hair loss (androgenetic alopecia) is usually thought of as an adult condition, but it can start in the teenage years. A review of the medical literature found 655 reported cases of pattern hair loss in people under 18. It concluded that it is not uncommon in this age group and is linked with a strong family history ⁷. In boys it often shows as a receding hairline or thinning crown; in girls as a widening parting. See hair loss in your 20s for how it tends to develop.

Hormonal and medical causes

Thyroid problems and polycystic ovary syndrome (PCOS) in teenage girls can contribute to hair thinning. Signs such as irregular periods, acne or extra body hair are worth mentioning to a doctor. See thyroid and hair loss and PCOS and hair loss.

What parents can do

• Stay calm and avoid making the teenager feel blamed or embarrassed
• Look at the pattern together: patches, overall thinning or breakage?
• Ask about recent illness, stress, dieting or new hairstyles
• Take photos to track changes over a few weeks
• Encourage regular meals and gentle hair care

Treatment in teenagers

Treatment depends on the cause, which is why a proper assessment matters. Fungal infections need prescription medicine. Shedding after illness usually settles on its own. Alopecia areata may be treated by a dermatologist.

For early pattern hair loss, the review noted that topical minoxidil has been used with success in under-18s, but it is not approved for this age group, and other treatments are poorly studied in children ⁷. Teenagers should not start minoxidil, finasteride or other hair loss medicines bought online without seeing a doctor first. Our guide to minoxidil explains what it is.

When to see a doctor

Book a GP visit if:

• There are bald patches, or a scaly, itchy or sore scalp
• Shedding is heavy or lasts more than a few months
• There are signs of hair pulling
• There are other symptoms such as tiredness, weight change or irregular periods
• The hair loss is affecting mood, school or social life

The GP may examine the scalp, ask questions and sometimes order blood tests, or refer to a dermatologist ⁸.

The bottom line

Hair loss in teenagers usually has a cause that can be found, from patchy alopecia and fungal infection to stress, diet, hairstyles or early pattern hair loss. Most causes can be managed, and many settle by themselves. Early, calm assessment helps both the hair and the teenager's confidence.

Frequently asked questions

Is it normal for a teenager to lose hair?

Some daily shedding is normal. Bald patches, heavy shedding, a scaly scalp or gradual thinning are worth getting checked ^{1 3}.

Can teenagers get pattern baldness?

Yes. A review found it is not uncommon in under-18s and is linked with a strong family history ⁷.

Can stress cause hair loss in teenagers?

Major stress or illness can trigger telogen effluvium, which usually tapers back to normal over about six to nine months ³.

Can a teenager use minoxidil?

It is not approved for under-18s. A doctor should assess the cause first and advise on any treatment ⁷.

Educational content. Not medical advice.