What should you know about right flank pain before period?

Pain before menstruation is often felt low in the abdomen or back, and pelvic cramping can spread to one side. Muscle tension, bloating, or changes in posture during premenstrual symptoms may also be felt near the flank. The timing alone does not prove that the pain is period-related. A kidney stone can cause one-sided pain that comes in waves, while a kidney infection commonly presents with flank pain, fever, chills, and feeling unwell. Burning or frequent urination can occur with a urinary tract infection. Keep track of whether the pain follows the same cycle and whether it disappears after bleeding starts.

Keep a simple symptom record for several cycles: date, side, severity, bleeding, urinary symptoms, bowel changes, and triggers. Gentle movement, rest, a warm pack over the lower back, and regular fluids may help mild cramping. Take an over-the-counter pain reliever only if it is suitable for you and follow the label; ask a pharmacist if pregnancy is possible or you have kidney, stomach, or bleeding concerns. Book an assessment when pain is new, persistent, repeatedly one-sided, or different from your usual period symptoms.

Seek urgent help for severe or escalating pain, fainting, heavy bleeding, fever, repeated vomiting, shoulder-tip pain, or a positive pregnancy test with one-sided pain. Prompt assessment is also needed for flank pain with chills, painful urination, blood in the urine, or inability to pass urine. Do not wait for the period to finish if you feel acutely unwell. A clinician can distinguish menstrual pain from urinary, pregnancy-related, or other pelvic causes.

Could the pattern fit menstrual pain, or should my urine and pregnancy status be checked? What symptoms would make this an urgent problem? Would a symptom diary help guide assessment?