A hormone is a chemical made by glands in the body and carried in the blood to other organs, where it changes how they work.
Oestrogen, progesterone, testosterone, cortisol and thyroid hormones are examples. They affect sleep, energy, mood and attention, among other things.
Oestrogen affects dopamine activity, and dopamine is involved in attention and motivation. Many women with ADHD describe their attention, mood and irritability changing across the menstrual cycle, after giving birth and during perimenopause. Some first recognise their ADHD in their forties, when hormonal change stops long-standing coping strategies from working.
Thyroid problems can also look like attention difficulties or low mood, so a clinician may suggest blood tests to check. Our Female-Presentation ADHD Screener asks about cycle-related changes directly.