What could be the reason if a teenage girl's menstruation is delayed by half a month and still hasn't started?

Generally, if a young girl's menstrual period is delayed by half a month or does not occur as expected, it may be caused by pregnancy, long-term use of medications, endocrine disorders, hyperthyroidism, polycystic ovary syndrome (PCOS), and other factors. Treatment should be based on the specific situation. The details are as follows:

1. Pregnancy

If a female is of childbearing age or has regular sexual activity, pregnancy is a possibility. If menstruation is absent for more than half a month, she can visit a hospital to undergo tests such as ultrasound to confirm whether she is pregnant. This is considered a normal physiological condition and usually does not require treatment. It is advisable to consume more high-protein foods such as fish, shrimp, and pork ribs in daily diet, which benefits fetal development.

2. Long-term Use of Medications

Long-term use of contraceptive pills can prevent the union of sperm and egg. These pills contain large amounts of estrogen, and prolonged use may interfere with the normal hormone secretion function of the ovaries, leading to amenorrhea (absence of menstruation). Generally, no specific treatment is required; reducing or discontinuing the use of contraceptive drugs can help alleviate symptoms.

3. Endocrine Disorders

Chronic smoking, alcohol consumption, staying up late, or excessive dieting may lead to endocrine imbalance. When the function of the hypothalamic-pituitary-ovarian axis is affected, insufficient gonadotropins are secreted, thereby disrupting the normal menstrual cycle and causing delayed menstruation. Correcting unhealthy lifestyle habits, maintaining regular sleep patterns, and ensuring a balanced, nutritious diet can gradually restore normal menstrual cycles.

4. Hyperthyroidism

Excessive secretion of thyroid hormones places the body in a state of high metabolism, which can disrupt the menstrual cycle. It is recommended to take medications such as methimazole tablets or carbimazole under medical supervision to suppress thyroid hormone production and improve symptoms.

5. Polycystic Ovary Syndrome (PCOS)

Menstruation is regulated by ovarian hormones. In PCOS, multiple small cyst-like changes develop within the ovaries, leading to hormonal imbalances. It is recommended to take medications such as drospirenone-ethinyl estradiol tablets, ethinyl estradiol-cyproterone acetate tablets, or desogestrel-ethinyl estradiol tablets under a doctor’s guidance to suppress follicle-stimulating hormone secretion and improve symptoms.

In addition, conditions such as endometrial tuberculosis could also be responsible. It is advised to seek medical evaluation for appropriate diagnostic tests, identify the exact cause, and receive targeted treatment accordingly.