What it measures
- CA-125
What is CA-125?
CA-125 is a protein that can be raised when ovarian cancer is present. It can also be raised by periods, pregnancy, endometriosis, fibroids, pelvic inflammatory disease and liver conditions, and it can be normal in early ovarian cancer. So it isn’t a diagnosis on its own.
Using CA-125 well
CA-125 is most useful alongside symptoms and an ultrasound scan of the ovaries. Our Pelvic Harmony Scan or, after the menopause, the Golden Years Scan can be booked alongside it.
If you have persistent bloating, pelvic or tummy pain, feel full quickly or need to pass urine more often, especially if you’re over 50, please see your GP.
Who it’s for
- Persistent bloating, feeling full quickly or pelvic pain
- A family history of ovarian cancer
- Monitoring a known ovarian condition
How to prepare
- Drink plenty of water beforehand; it makes the sample quicker and easier to take.
- You don’t need to fast.
- If you still have periods, avoid testing during your period, as it can raise CA-125.
Ovarian Cancer Marker (CA-125) Blood Test: your questions
Can CA-125 detect ovarian cancer early?
Not reliably on its own. CA-125 can be normal in early ovarian cancer and raised for many other reasons. It’s used together with symptoms and a pelvic ultrasound.
Information on this page is general and doesn’t replace advice from your GP, midwife or consultant. If you feel unwell or are worried about symptoms, contact your GP, call NHS 111 or, in an emergency, 999.