CA 19-9

Optimal Result: 0 - 35 U/mL.

Other names: cancer antigen 19-9, carbohydrate antigen 19-9, CA 199 measurement, CA 19-9 radioimmunoassay (RIA)

A CA 19-9 test measures the amount of a protein called CA 19-9 (cancer antigen 19-9) in a sample of your blood. CA 19-9 is a type of tumor marker. Tumor markers are substances made by cancer cells or by normal cells in response to cancer in your body.

Healthy people can have small amounts of CA 19-9 in their blood.

Why do I need a CA 19-9 test?

- Monitor certain types of cancer and cancer treatment. CA 19-9 levels often go up as cancer grows and go down as tumors shrink.

- Help predict how cancer may behave over time.

- Check whether cancer has returned after treatment.

Help diagnose certain cancers and other diseases when used with other tests.

You may need a CA 19-9 blood test if you've been diagnosed with pancreatic cancer or another type of cancer that causes high CA 19-9.

These include cancers of the:

- Bile duct

- Colon and rectum

- Stomach

- Ovaries

- Bladder

Learn more about laboratory tests, reference ranges, and understanding results.

Is there anything else I need to know about a CA 19-9 test?
Labs use different methods to measure the amount of CA 19-9 in your blood sample. The test method can affect your results. If you're having regular tests to monitor cancer, it's important to have your tests done the same way, and usually in the same lab. This allows your provider to compare your results over time. Your test report usually says what method was used to measure your CA 19-9 levels. If you have any questions about how your tests are done, talk with your provider.


Goonetilleke KS, Siriwardena AK. Systematic review of carbohydrate antigen (CA 19-9) as a biochemical marker in the diagnosis of pancreatic cancer. Eur J Surg Oncol. 2007 Apr. 33(3):266-70. [QxMD MEDLINE Link].

Steinberg W. The clinical utility of the CA 19-9 tumor-associated antigen. Am J Gastroenterol. 1990 Apr. 85(4):350-5. [QxMD MEDLINE Link].

Bonheur J. Biliary Obstruction. Medscape Drugs and Diseases. Available at

Shojamanesh H. Cholangitis. Medscape Drugs and Diseases. Available at

Rowe W. Inflammatory Bowel Disease. Medscape Drugs and Diseases. Available at

Gardner T. Acute Pancreatitis. Medscape Drugs and Diseases. Available at

Wolf D. Cirrhosis. Medscape Drugs and Diseases. Available at

Sharma G. Cystic Fibrosis. Medscape Drugs and Diseases. Available at

Nickloes T. Bile Duct Tumors. Medscape Drugs and Diseases. Available at

Dragovich T. Colon Adenocarcinoma. Medscape Drugs and Diseases. Available at

Cabebe E. Gastric Cancer. Medscape Drugs and Diseases. Available at

Tian SB, Yu JC, Kang WM, Ma ZQ, Ye X, Cao ZJ, et al. Combined Detection of CEA, CA 19-9, CA 242 and CA 50 in the Diagnosis and Prognosis of Resectable Gastric Cancer. Asian Pac J Cancer Prev. 2014. 15(15):6295-300. [QxMD MEDLINE Link].

Green A. Ovarian Cancer. Medscape Drugs and Diseases. Available at

Axelrod D. Hepatocellular Carcinoma. Medscape Drugs and Diseases. Available at

Herbella F. Esophageal Cancer. Medscape Drugs and Diseases. Available at


What does it mean if your CA 19-9 result is too high?

High levels of CA 19-9 are often a sign of pancreatic cancer. But high levels can also be a sign of other types of cancer or certain conditions that aren't cancer. For example, gallstones and cirrhosis of the liver can cause high CA 19-9 levels.

Because high levels of CA 19-9 can mean different things, the test is not used by itself to screen for or diagnose cancer or other diseases. But it can help monitor your cancer and check how well your treatment is working.

During cancer treatment, your health care provider may test you on a regular basis to see if your treatment is working.

After your treatment is complete, you may need to have CA 19-9 tests to check whether the cancer has come back. High levels of CA 19-9 may be one of the first signs that cancer cells are growing again.

If you don't have cancer but your test results show a high level of CA 19-9, you may not a health problem that needs treatment. Healthy people can have high CA 19-9 levels. But high levels may be a sign of a condition, such as:

- Pancreatitis, inflammation of the pancreas

- Gallstones

- Bile duct disease, including a blockage or infection

- Liver disease

- Cystic fibrosis

Talk with your provider about what your results may mean. If your provider thinks you may have one of these conditions, you will probably need other tests to find out for sure.

10 000+ happy customers
100% satisfaction
★ ★ ★ ★ ★ customer support

Understand blood, stool, and urine medical results from all your laboratories.

Upload Your Personal Results

Upload Personal Results

For professional account plans go here

for professional account plans go here

Monthly plan

Annual plan

Own it for life

  • Subscription
  • Data entry service included

    Data entry service

    Our exclusive data entry service is a convenient way to get your results into your private dashboard. Simply attach an image or a file of your lab test results, and one of our qualified data entry team members will add the results for you. We support all sorts of files, whether PDFs, JPGs, or Excel. This service is excellent whether you have a lot of reports to upload or are too busy to do the data entry yourself.

  • Instant interpretation
  • Use free data entry form

    Free data entry form

    We strive to make the data entry process easy for you. Whether by offering dozens of templates to choose from that pre-populate the most popular laboratory panels or by giving you instant feedback on the entered values. Our data entry forms are an easy, fast, and convenient way to enter the reports yourself. There is no limit on how many lab reports you can upload.

  • 4000+ biomarkers explained
  • Nutrition recommendations
  • Cancel anytime


$15 /month

billed every month

  • monthly
  • $15 per report
  • ✓ Instant interpretations
  • ✓ 4000+ biomarkers explained
  • ✓ Nutrition recommendations
  • ✓ Free data entry form
  • ✓ Unlimited data
  • ✓ $15 data entry service
  • ✓ Cancel anytime

Most popular

Data entry included


$79 /year

$6.60/month billed annually

  • yearly
  • 5 reports free
  • ✓ Instant interpretations
  • ✓ 4000+ biomarkers explained
  • ✓ Nutrition recommendations
  • ✓ We enter 5 reports for you
  • ✓ Yearly subscription
  • ✓ Cancel anytime

Data entry included


$250 /once

own it for life

  • pay once
  • 10 reports free
  • ✓ Instant interpretations
  • ✓ 4000+ biomarkers explained
  • ✓ Nutrition recommendations
  • ✓ We enter 10 reports for you
  • ✓ No subscription
  • ✓ Dedicated support
  • ✓ Unlimited access

Are You a Health Professional?

Get started with our professional plan

Welcome to Healthmatters Pro.

Save time on interpreting lab results with the largest database of biomarkers online. In-depth research on any test at your fingertips, all stored and tracked in one place. Learn more

Pro Monthly Plus

for health professionals

  • ✓ Track multiple clients results
  • ✓ No setup fees
  • ✓ No hidden costs
  • ✓ Instant interpretations
  • ✓ 4000+ biomarkers explained
  • ✓ Includes data entry service
  • ✓ Personal training and support
  • ✓ Cancel anytime

$75 per month

Use promo code to save 10% off any plan.

We implement proven measures to keep your data safe.

At HealthMatters, we're committed to maintaining the security and confidentiality of your personal information. We've put industry-leading security standards in place to help protect against the loss, misuse, or alteration of the information under our control. We use procedural, physical, and electronic security methods designed to prevent unauthorized people from getting access to this information. Our internal code of conduct adds additional privacy protection. All data is backed up multiple times a day and encrypted using SSL certificates. See our Privacy Policy for more details.