Premenopause broadly means the time before menopause. Perimenopause is the transition leading up to it, often beginning in the 40s. Estrogen and progesterone fluctuate, and estrogen declines overall. Your age or hair alone cannot tell you which stage you’re in.[1]
Each follicle cycles through growth and rest. Hormones help regulate that cycle. Female pattern hair loss becomes more common around and after menopause, but genetics also matter and the hormonal link is not fully understood.[2] [3]
In female pattern hair loss, affected follicles produce progressively finer, shorter hairs. That can mean less coverage and a wider-looking part. This is different from a strand snapping along its length, and it cannot be diagnosed from your age.[7]
Not every change is hormonal. Illness, significant stress, weight loss and some medicines can cause shedding; heat, chemical processing and rough handling can contribute to breakage. More than one thing may be happening.[3] [5]