Why Hypothyroidism Causes Hair Loss
Your hair follicles are among the most metabolically active tissues in your body, so they're sensitive to thyroid hormone, which regulates their growth cycle. When thyroid hormone is low, more follicles shift out of the growing phase and into the resting and shedding phase at once. Because hair grows slowly, you often don't notice the increased shedding until weeks or months later — by which point your hair can look noticeably thinner overall.
What Thyroid Hair Loss Looks Like
Hypothyroid hair loss is typically diffuse — a general thinning across the whole scalp rather than distinct bald patches. The hair may also become dry, brittle, and more prone to breakage. A classic and telling clue is thinning or loss of the outer third of the eyebrows. Many people also notice the change alongside other thyroid symptoms like fatigue, weight gain, feeling cold, and dry skin.
Does Hair Grow Back After Treating the Thyroid?
In most cases, yes. Because thyroid-related hair loss comes from disrupting the growth cycle rather than permanently destroying follicles, restoring healthy thyroid levels typically allows the hair to regrow — though it takes patience. Hair grows slowly, so it can be several months before you see meaningful regrowth after your thyroid is optimized. Consistency with treatment is what pays off.
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Schedule Your ConsultationHow Optimizing Your Thyroid Helps
The most effective fix for thyroid hair loss is treating the thyroid itself. thyroid optimization — comprehensive testing and personalized treatment to bring your thyroid to optimal, not just “normal” — gives your follicles the environment to return to a healthy growth cycle. Addressing related deficiencies (iron, vitamin D, selenium) often involved in both thyroid health and hair helps too.
When to Get Your Thyroid Checked
If you're losing hair along with other signs of an underactive thyroid, it's worth a complete thyroid panel as part of comprehensive hormone testing. Treating the thyroid is often the key to stopping the shedding and getting your hair back.
Focal Point Vitality is a Scottsdale clinic serving patients throughout Arizona — in person at our Scottsdale office or by concierge virtual visit (Arizona patients only).
Frequently Asked Questions
Can hypothyroidism cause hair loss?
Yes — low thyroid hormone disrupts the hair growth cycle, pushing more follicles into shedding at once. It usually causes diffuse thinning and can include loss of the outer eyebrows.
Will my hair grow back if I treat my thyroid?
In most cases yes — thyroid hair loss is usually reversible because the follicles aren't permanently damaged. Regrowth takes patience, often several months after your thyroid is optimized.
What does thyroid hair loss look like?
Typically diffuse thinning across the whole scalp (not patchy), with dry, brittle hair, and often thinning of the outer third of the eyebrows — usually alongside other thyroid symptoms.
How do I get my thyroid checked in Scottsdale?
Book a consultation. We'll run a complete thyroid panel, interpret it against optimal ranges and your symptoms, and build a personalized plan — in person in Scottsdale or by concierge virtual visit across Arizona.