Causes & Triggers

Testosterone doesn’t directly cause baldness — a byproduct called DHT and genetic sensitivity to it do. Here’s how the link actually works.

Hats don’t cause pattern hair loss, but tight bands, poor hygiene or friction can play a small supporting role. Here’s what actually happens.

Why fever, surgery or major illness can trigger hair shedding months later, and what tends to happen next.

Many common prescriptions can trigger hair shedding. Here’s how medication-related shedding works and what questions to ask your prescriber.

A plain-language guide to iron, ferritin and hair shedding, and the specific questions worth raising at your next doctor’s visit.

Thyroid conditions can trigger diffuse hair thinning. Here’s how the thyroid affects hair growth, what to watch for, and when to see a doctor.

Yes, some diets can trigger hair shedding. Here’s how nutrition, crash dieting and deficiencies relate to hair loss, and what doesn’t.

Genetics play a major role in hair loss, but not the whole story. Here’s what heredity actually determines and what it doesn’t.

Yes, stress can trigger hair shedding, usually through a temporary condition called telogen effluvium. Here’s how it works and what to watch for.

Losing hair every day is normal. Here’s the general range people cite, what affects it, and when shedding is worth a doctor’s look instead.