Home kit
CA 125 Test
CA 125, a blood protein doctors use alongside symptoms and an ultrasound scan when possible ovarian problems are being assessed.
- Doctor-reviewed results
- Laboratory analysis
- 1 to 2 working days from lab receipt
- No fasting required
What’s included
1 marker measured
CA 125
CA125 is a blood marker that can be raised in ovarian cancer. It is not specific: other causes of a raised level include endometriosis, pelvic inflammatory disease, pregnancy, a twisted, burst or bleeding ovarian cyst, heart failure, disease or irritation of the abdominal lining and some other cancers.
Overview
CA 125 is used to follow up a result that was raised before, or when a doctor has asked for it. If you keep having bloating, feeling full quickly, pelvic pain or needing to pass urine more often, the NHS advises seeing your GP, who can arrange CA 125 and a scan if needed. This test can sit alongside that appointment, not in place of it.
CA 125 is a protein that rises when the lining of the abdomen or pelvis is irritated. Endometriosis, fibroids, periods, pregnancy and infection can all raise it, which is why it is never read on its own. In the NHS, a GP uses it for people aged 40 and over with ongoing symptoms such as bloating, feeling full quickly or pelvic pain, and arranges an ultrasound scan depending on age and the result. If you have these symptoms, see your GP first: this test does not replace that appointment, and a normal result does not settle them.
Who this is for and who it isn’t
Who it’s for
- Women aged 40 and over
- Anyone following up a previously raised CA 125
- Women whose doctor has asked for a CA 125 result
Who it isn’t for
- CA 125 is never read on its own, and it is not a screening test: it is not accurate enough to be used in women without symptoms, which is why no national programme uses it. It rises with endometriosis, fibroids, periods, pregnancy and infection, so a raised result usually has a benign explanation. A normal result does not settle persistent symptoms either.
- If you have symptoms that keep coming back, see your GP first, whatever this shows; an ultrasound scan is normally part of the answer. This test is for women aged 40 and over, the age from which NICE uses CA 125 to assess these symptoms.
- Anyone with a new, severe or worsening symptom: contact your GP or call NHS 111. A test you buy today is not a substitute for being examined.
Common reasons people choose this test
- Following up a previously raised CA 125
- A doctor has asked for a CA 125 result
- Symptoms you are already seeing your GP about, such as bloating or pelvic pain
These are reasons people choose to test, not signs that something is wrong. A result is one part of a picture your doctor puts together with your history and an examination.
What your result looks like
Every result is shown with the unit and the reference range exactly as the laboratory reported it, with the doctor’s note underneath.
- CA 125▲ High
- Result
- 58 kU/L
- Range
- <35
| Marker | Result | Units | Range | Flag |
|---|---|---|---|---|
| CA 125 | 58 | kU/L | <35 | ▲ High |
Doctor’s note (example)
CA 125 is above the range. Endometriosis, fibroids, periods, infection and pregnancy all raise it, so most results at this level have a benign explanation. It is never read alone, and a clinician would usually arrange an ultrasound scan alongside.
Values above are examples. Your report shows your own results with the laboratory’s units and reference range for your age and sex, reviewed, signed and released by a GMC-registered doctor.
How it works
- Your kit arrivesPosted to your door, with instructions and what you need to send your sample back.
- You take your sampleFinger-prick sample at home, or a clinic blood draw, your choice
- The laboratory analyses itYour sample is processed for the measurements included in this test. Lab processing typically takes 1 to 2 working days from receipt of your sample.
- A doctor reviews and releases itA GMC-registered doctor reads every result and signs the report before it reaches you.
- Sample
- Home finger-prick kit
- Preparation
- No fasting required
- Who it's for
- Women · ages 40+
How to prepare
What we can and can’t tell you
The reference range beside each result is the laboratory’s own. A result in range is not a clean bill of health and a result outside it is not a diagnosis. Most ranges cover about 95% of healthy people, so about 1 in 20 healthy people fall just outside any one range. No test result replaces an examination or your own doctor’s judgement, and none of these panels is a cancer screening programme.
Read the full note
The reference range printed beside each of your results is the laboratory's own, and it is the range that applies to your result. We do not apply a second range of our own, and we do not tell you that a result the laboratory reported as normal is nonetheless too low or too high. If you see a claim elsewhere that your result ought to sit inside a narrower band than the one the laboratory printed, treat it with caution and ask your doctor.
Some assays cannot give an exact figure above or below a certain point, and those results are reported the way the laboratory sends them, for example as a value greater than a stated number. A result in range is not a clean bill of health, and a result outside a range is not a diagnosis: most reference ranges are set to cover about 95% of healthy people, so some healthy people fall just outside them. No blood test replaces an examination, a scan or your own doctor's judgement, and none of these panels is a screening programme for cancer.
If you have a symptom that is new, severe, or getting worse, contact your GP or NHS 111 rather than waiting for a test result. In an emergency call 999.
Frequently asked questions
Does the time of my cycle matter?
Yes, a little. CA 125 can rise around a period and with endometriosis, so a sample taken outside your period gives a cleaner reading.
Should I use this to screen for ovarian cancer?
No. It is not accurate enough for screening in women without symptoms, and UK guidance is clear on that. It is used to help assess symptoms alongside an ultrasound, and that is the setting it belongs in.
What if it comes back raised?
The commonest explanations are not cancer, and the reviewing doctor explains that plainly. The usual next step is a GP appointment and an ultrasound scan, and we say so in the report rather than leaving you to work it out.
Can it be normal and something still be wrong?
Yes. A proportion of ovarian cancers, particularly early ones, do not raise CA 125. That is why persistent symptoms are taken seriously whatever the number says.
Does biotin affect the result?
It can. High-dose biotin (vitamin B7), often sold for hair, skin and nails, can make some hormone results read too high or too low. Laboratory advice is usually to leave at least 8 hours after a dose of 5 mg or more, and some advise longer, so the simplest approach is to skip it on the day of your sample. Tell us if you take it, and do not stop a medicine that a doctor has prescribed.
How long do results take?
The laboratory typically takes 1 to 2 working days from receiving your sample. This does not include kit delivery, sample collection or return postage. A doctor reviews your results before they are released.
Can I choose a home kit or a clinic?
Both, it is your choice at checkout. Either collect a finger-prick sample at home with the posted kit and send it back as the instructions explain, or book a clinic appointment and have a trained clinician take the sample for you.
Is a doctor involved?
Yes. Every result is reviewed by a GMC-registered doctor who signs it off and explains what it means and what to do next.
Is it confidential?
Your results are available through your secure patient portal. Our privacy policy explains how your information is handled and when it may be shared to provide your care.
What happens to my sample and results?
Your sample is analysed at a UKAS-accredited laboratory (ISO 15189). A GMC-registered doctor then reads every result and signs the report before it is released, so nothing reaches you unreviewed. There is no option to receive results without a doctor reading them first. The report arrives in your secure portal in plain English: each result with its unit and the laboratory's own reference range, and the doctor's note on what the set means read together. If a result sits outside its range the report says so and explains what usually happens next, which is most often a conversation with your own GP, who can act on it alongside your history and examination. Most reference ranges are set to cover about 95% of healthy people, so about 1 in 20 healthy people fall just outside any one of them. On a report with many results it is common for one to sit just outside its range, and a single number on its own rarely tells the whole story. If a result needs urgent attention, the reviewing doctor is alerted straight away and we contact you by phone the same working day rather than leaving it in the portal for you to find. If a specific result needs rechecking, the reviewing doctor says so in your report.
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