CA-125 blood test
Quick answer: A CA-125 test measures a protein that can be raised in ovarian cancer but also in common non-cancer conditions such as endometriosis, fibroids, periods and pregnancy. Doctors order it to look into an ovarian mass or to follow ovarian cancer treatment; it is not used on its own to screen healthy women.
- SampleBlood
- TakesAbout 5 minutes
- Before the testNo special preparation is usually needed; your doctor may avoid testing during your period.
- In fertility careCA-125 can be raised with endometriosis, which is a common cause of fertility problems, so it is read with scan findings.
How the test is done
- 1Your doctor may avoid scheduling the test during your period
- 2The inside of your elbow is cleaned
- 3A needle draws blood into a tube
- 4Your doctor reads the result with your scan findings
What your results can mean
Reading your report
A raised level does not mean cancer on its own, so discuss your result with your doctor.
If the result is outside the usual range
A high level can be seen with ovarian cancer, but also with endometriosis, fibroids, pelvic infection, periods, pregnancy and liver disease. A normal level does not rule out every ovarian cancer.
Who usually has this test
Women with an ovarian cyst or mass on a scan, women being followed after ovarian cancer treatment, and sometimes women with suspected endometriosis.
Risks and aftercare
Apart from a possible small bruise, nothing special is needed.
Names and options
Also called: CA 125, cancer antigen 125, ovarian tumour marker
Listed by the hospital as
- CA 125, SERUM
Questions about this test
Does a high CA-125 mean I have cancer?
Not necessarily. CA-125 can rise with endometriosis, fibroids, pelvic infection, periods and pregnancy. Your doctor reads it with your scan and symptoms.
Can CA-125 diagnose endometriosis?
No. It can be raised in endometriosis but is not reliable enough to confirm or rule it out. Scans and sometimes laparoscopy are used for diagnosis.
Why is CA-125 not used to screen healthy women?
It can be raised by many common non-cancer conditions and can be normal in early cancer. Used alone, it can cause worry and unnecessary tests.
Related tests
Tamara Hospital & IVF Centre, Rajajinagar
34/3, 10th Cross Road, opp. Vardhaka Sardar Patel School, 1st N Block, 2nd Stage, Rajajinagar, Bengaluru 560010
The hospital is open 24 hours. Call before you come to check the timing for your scan or sample collection.
Get directions ↗IVF Pulse fertility care at Tamara Hospital →
Reception
Waiting area
IVF lab
This page explains each test in general terms so you know what to expect. It is not medical advice: your doctor decides which tests you need and what your results mean. Reference ranges differ between laboratories. Updated 4 November 2026.