Everything You Need to Know About Hair Lossand How to Treat It Hair loss affects women of all ages. Here's why it happens,and what you can do about it. Hormonal changes are among the most common causes of hair loss. Lars Skjoth, Harklinikken Clinic Hormonal changes arealso responsible forpostpartum hair loss. Hair loss is also common during perimenopause and menopause. Dieting (specifically yo-yodieting and a lack of nutrients)can play a role in hair loss. So can stress and genetics.