8 Reasons Why Your Hair Is Getting Thinner—and How to Fix It
Potential cause: Major stress
Why it leads to thinning: Physiological stress, whether it's from a breakup, the loss of a loved one or a traumatic physical event (childbirth is a classic example), can shift hair follicles into rest mode, where they stop producing hair. It's called telogen effluvium, and it's very common, says Pamela Jakubowicz, MD, a dermatologist at Montefiore Medical Center, in New York. Because of hair's growth cycle, you'll notice thinning roughly 3 months after the stressful event.
How to fix it: Telogen effluvium generally resolves on its own. You should notice improvement about 3 months after stress levels return to normal.
Potential cause: Medications
Why it leads to thinning: Some drugs are known to cause hair thinning. Prime examples: hormonal birth control, isotretinoin for acne, blood pressure medications, cholesterol-lowering drugs and certain antidepressants.
How to fix it: Minoxidil may help, but if your hair loss is affecting your well-being, Sejal Shah, MD, a board certified dermatologist in New York, recommends asking your prescribing doctor if there are other medications you can try that don't have that as a side effect.
Potential cause: Frying your hair with hot tools
Why it leads to thinning: High heat creates air bubbles within the hair shaft that can cause breakage. If tools get too close to the root, they can damage the hair follicle.
How to fix it: Medium heat is best—if your hot tools have an intensity range between 1 and 10, for example, set them at 5. Keep hot styling tools at least an inch or two away from your scalp to protect the follicle.
Potential cause: A thyroid disorder
Why it leads to thinning: Thyroid issues lead to hair loss because follicles can't get resources they need to produce hair, says Jakubowicz. In hypothyroidism, it's because your whole system is moving slower; in hyperthyroidism, it's likely because your body is depleting resources faster.
How to fix it: If your dermatologist suspects a systemic condition like a thyroid problem is causing your thinning, they'll refer you to your internist for testing and treatment, which should also help with the hair loss.