CA 125
What this test measures
CA 125 is a protein released by the lining of the abdomen and pelvis and by some cells in the ovary. Tumour markers are proteins that can rise for many reasons, most of them not cancer. Specialists mainly use them to follow a condition that has already been identified, and a single value cannot answer a screening question on its own.
Why doctors request it
UK GPs request it in women with persistent bloating or pelvic symptoms, and specialists use it to follow ovarian conditions after treatment.
What commonly pushes it up
- Menstruation, pregnancy and endometriosis
- Fibroids and ovarian cysts
- Pelvic inflammation or infection
- Any inflammation of the abdominal lining, including liver disease with fluid
- Heart failure
- Ovarian cancer and some other cancers
What commonly pushes it down
- After the menopause it tends to run lower
Everyday reasons for a value outside the range
- It rises during a period, so timing in the cycle matters
- Endometriosis and fibroids are common benign causes
- A value a little above the range in a woman before the menopause is more often benign than not
About the sample
Best taken outside a period. Read with pelvic ultrasound rather than alone.
Upload a photo or PDF and see every line against the range your lab printed, explained in plain English. First report free.
Read my report freeThis is an educational summary of results you uploaded. It is not medical advice, a diagnosis or a treatment plan, and it does not replace the doctor who requested the test. If you are worried, or a result is marked outside range, discuss it with your doctor. Written and reviewed by a UK consultant physician. Reference ranges vary between laboratories.