Thinning Hair in Your 40s: The Causes Worth Checking First
A wider parting, a thinner ponytail, more hair in the plughole. Hair loss in women is common, often treatable — and worth investigating rather than hiding.
Photo: Pexels
Key takeaways
- Female pattern hair loss, shedding after stress or illness, low iron and thyroid problems are among the most common causes.
- A doctor can check for treatable causes with simple blood tests.
- Topical minoxidil is an approved treatment for female pattern hair loss, but it takes months to work.
- Sudden patchy loss, scalp pain or redness should be seen promptly.
Losing around 50 to 100 hairs a day is normal.1 But if your parting looks wider, your ponytail feels thinner or you can see more scalp under bathroom lights, you are far from alone: hair thinning is extremely common in women, especially from the forties onwards.
The usual suspects
Female pattern hair loss. The most common cause. Hair gradually thins over the top and crown, with the front hairline usually kept. It often runs in families and becomes more noticeable around menopause.3
Telogen effluvium. A sudden increase in shedding a few months after a trigger such as illness, surgery, childbirth, crash dieting or major stress. It usually settles by itself once the trigger has passed.2
Low iron or other deficiencies. Heavy periods — common in perimenopause — can lower iron stores, which is linked to shedding.
Thyroid problems. Both an underactive and an overactive thyroid can cause thinning.
Hair care habits. Tight ponytails, braids and frequent heat or chemical styling can damage hair and, over time, the follicles.
What to ask your doctor
Bring photos taken a few months apart and a list of any recent illness, medication changes or stress. A doctor may suggest blood tests for iron levels, thyroid function and other factors, and can refer you to a dermatologist if the cause is unclear.1
Treatments with evidence
- Topical minoxidil is approved for female pattern hair loss. It needs to be used daily, may cause extra shedding for the first few weeks, and results take around six months to judge.2
- Treating the cause — replacing iron, correcting thyroid levels — can allow hair to recover.
- Other options, such as certain prescription tablets, are sometimes used under specialist supervision.
Be sceptical of supplements promising thicker hair. Unless you are deficient in something, extra vitamins are unlikely to help.
When to get help quickly
See a doctor soon if hair is falling out in patches, if your scalp is red, sore, scaly or itchy, or if you are losing hair along with other symptoms such as unexplained tiredness or weight change.
Sources
- NHS. Hair loss. nhs.uk.
- American Academy of Dermatology. Hair loss in women: causes and treatment. aad.org.
- British Association of Dermatologists. Female pattern hair loss (patient information leaflet). bad.org.uk.