Adult acne in women may be triggered by hormonal changes – eg: pregnancy, or taking the contraceptive pill. Stress can also cause changes in hormones that can lead to spots. Acne is also one of the symptoms of Polycystic Ovarian Syndrome (PCOS), a condition that affects 1 in 10 women. Other symptoms may include menstrual irregularities, mood swings, weight gain, excess hair growth (on face and body), and fertility problems. For some people, certain foods may be a trigger, for example cow’s milk.