Hello Good Evening, Your daughter has missed period, which is due to some common reason like: -Pregnancy -Menopause -Stress and anxiety -Excessive weight loss, or weight gain -Hormonal imbalance -Hypothyroidism -PCOS Pregnancy and menopause are not applicable here but any of others can be a cause for this, so please go through proper evaluation to get other causes like hormonal imbalance or PCOS. PCOS (Polycystic ovary syndrome) produces symptoms in approximately 5% to 10% of women of reproductive age (12–45 years old). It is thought to be the most frequent endocrine problem in women of reproductive age. The principal features are anovulation, resulting in irregular menstruation, amenorrhoea, ovulation-related infertility, and polycystic ovaries; excessive amounts or effects of androgenic (masculinizing) hormones, resulting in acne and hirsutism; and insulin resistance, often associated with obesity, Type 2 diabetes, and high cholesterol levels. The symptoms and severity of the syndrome vary greatly among affected women. After excluding these, usually a short course of hormones is given,which is usually followed by withdrawal bleeding. Many a times menses resume to normal after this. If the following periods are delayed/irregular,it has to be further investigated So go to the gynecologist to get her evaluated for irregular periods. Regards, Dr. Naresh Jain.