What does it mean if menstruation is absent for two months?

Menstruation typically occurs once per month, with a normal cycle length of 28 days ± 7 days. If menstruation is absent for more than two months, this is definitely abnormal and warrants medical evaluation. So, what could cause the absence of menstruation for two months?

What Causes Absence of Menstruation for Two Months?

If menstruation has been absent for two months, the first step is to test serum or urinary human chorionic gonadotropin (hCG) to rule out pregnancy—including ectopic pregnancy and missed abortion. Aside from pregnancy, occasional amenorrhea is often linked to psychological or emotional factors in women, such as exam-related stress, excessive work pressure, or low mood. Pelvic ultrasound should also be performed. If the endometrium is thickened, progesterone therapy may be administered to induce menstruation.

If pregnancy has been excluded and menstruation remains absent for two months, pelvic ultrasound should be performed. Ultrasound primarily assesses endometrial thickness. If the endometrium has thickened to over 1 cm, and there is no progesterone production or ovulation, the endometrium will not undergo withdrawal bleeding and will continue proliferating. In such cases, exogenous progesterone (or a progestin) can be administered to transform the endometrium from the proliferative phase to the secretory phase; subsequent withdrawal of the medication triggers withdrawal bleeding—effectively inducing menstruation. However, even after such treatment, menstruation may still fail to resume. Additionally, reproductive endocrine disorders—such as polycystic ovary syndrome (PCOS)—may be responsible. In PCOS, abnormal hormonal secretion leads to elevated androgen levels, which suppress estrogen activity, resulting in oligomenorrhea, amenorrhea, and even infertility.

Therefore, if menstruation is absent for two months, patients should seek medical evaluation at a hospital, including pelvic ultrasound and hormonal assays, to establish an accurate diagnosis.