Fishy smell during your period: what to know

Menstrual blood can temporarily alter the vaginal environment, and a pad or tampon left in place for too long can develop an unpleasant smell. A fishy odour that continues outside the period, or appears with thin discharge, itching, burning, pelvic discomfort, or pain when urinating, may reflect bacterial imbalance or another infection.

The smell alone cannot identify the cause. A clinician may ask about products, cycle timing, symptoms, pregnancy possibility, and sexual contact, then recommend an examination or a vaginal sample test.

Change menstrual products regularly according to the product instructions and wash the external vulval area gently. Do not douche or use scented wipes, sprays, or vaginal washes. Choose breathable underwear and change out of damp clothing. Record whether the odour disappears when bleeding ends and whether other symptoms develop.

Book a gynaecology or sexual-health review if the smell is new, strong, recurrent, or remains after the period. If an infection is found, treatment is matched to the diagnosis; information about antibiotic treatment for pelvic infection is available here.

Get urgent help for severe pelvic pain, fever, faintness, vomiting, heavy bleeding, or a rapidly worsening smell with feeling unwell. Seek prompt advice if a retained tampon or other menstrual product is possible, or if pregnancy could be possible and pain or unusual bleeding is present.

Ask whether the odour fits a normal period-related change or needs testing, whether your menstrual product routine could contribute, which symptoms suggest infection, and whether you should avoid sex or particular products while waiting for results.