Why can an imperforate hymen cause periods to stop?

An imperforate hymen is present from birth and covers the vaginal opening without a passage. Once menstrual cycles begin, blood may collect behind this tissue instead of appearing as a period. This can cause cyclical cramping, pelvic pressure, lower back pain, constipation, painful urination or a feeling of fullness. Breast development and other puberty changes may still occur, so the absence of visible bleeding does not necessarily mean the menstrual system is not active.

Several other conditions can stop periods, including pregnancy, hormonal changes, low energy availability and some medicines. A clinician can assess the pattern, perform an appropriate examination and use imaging if needed to identify obstruction or another cause.

Arrange a medical appointment if periods have not started when expected or have stopped with recurring pain. Note when pain occurs, urinary or bowel changes, and any puberty or pregnancy-related symptoms. Avoid attempting to puncture or stretch the tissue. If an imperforate hymen is diagnosed, a clinician may recommend a procedure to create an opening and drain retained blood, followed by specific aftercare.

Get urgent help for severe pelvic pain, vomiting, fever, fainting, inability to urinate or rapidly worsening abdominal swelling. These signs can indicate significant pressure, infection or another problem requiring prompt examination.

Ask whether the bleeding is being blocked, whether an examination or ultrasound is appropriate, what treatment would release the obstruction, and how follow-up will confirm that menstrual flow is unobstructed.