Can a blood test check for cancer?
A cancer diagnosis is something no one wants to face, but early detection can make a real difference in treatment options and outcomes. Understandably, more people are now asking whether a simple blood test could reveal signs of cancer, or at least offer some peace of mind.
In this guide, we explore what blood tests can and can’t tell you about cancer, how they’re used in health screenings and how they can help you take a more proactive approach to your health.
How blood tests fit into cancer screening
Some blood tests can pick up markers or patterns that may be linked to certain cancers, but they’re not used in isolation to diagnose cancer.
Instead, they help build a picture of your overall health. Changes in blood cell counts, protein levels or organ function might suggest that something unusual is happening in the body, even if no symptoms are present. In these cases, your healthcare provider may recommend further investigation through imaging or specialist referral.
That’s why blood testing is often used as part of a broader screening process, particularly for those with increased risk factors such as age, lifestyle or family history.
What can blood tests show?
Blood tests can provide clues about your health in a number of ways. Here are some of the common types of blood tests used to investigate possible cancer risks:
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Full blood count (FBC): Measures different types of blood cells. Abnormal levels may suggest conditions like leukaemia or other blood-related cancers.
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Tumour markers: These are substances (usually proteins) made by cancer cells or by the body in response to cancer. Certain cancers are linked to specific markers, for example, PSA for prostate cancer or CA-125 for ovarian cancer.
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Liver function tests: Can detect abnormal proteins or enzymes that may indicate liver damage or disease, including liver cancer.
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Kidney function tests: Help assess how well your kidneys are working. Poor kidney function can sometimes be a sign of cancer affecting the urinary system.
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Inflammatory markers (like CRP): Chronic inflammation has been linked to an increased risk of some cancers. These markers can suggest whether inflammation is present in the body.
None of these results alone confirm cancer, and more likely to indicate other health issues, but they may raise enough concern for your healthcare provider to recommend further investigations.
What blood tests can’t do
It’s important to understand the limitations of blood testing too.
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Blood tests can’t guarantee the presence or absence of cancer.
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Not all cancers release markers or show up in bloodwork.
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Non-cancerous conditions, such as infections, autoimmune disorders or nutrient deficiencies can cause many changes detected in the blood.
So, while blood testing plays an important role in health screening, it’s just one part of the picture.
Are blood tests useful in routine cancer screening?
Yes, especially when they’re part of a broader health check-up.
Blood tests can help identify patterns and trends in your health, monitor changes over time and catch potential warning signs early. For people with a higher risk due to age or family history, they can be a valuable tool for reassurance or early intervention.
At Bluecrest Wellness, we offer dedicated Male and Female Cancer Risk packages that use specific blood tests alongside other samples. These packages include checks for key cancer markers, as well as other health indicators like inflammation, cholesterol, diabetes risk and liver and kidney function.
What cancers can blood tests help detect or monitor?
While no test can screen for every type of cancer, some blood tests are linked to specific cancer types. For example:
Prostate cancer The PSA (Prostate-Specific Antigen) test measures the level of PSA in your blood. High levels don’t always mean cancer is present, but they may trigger further testing.
Ovarian cancer The CA-125 marker is often raised in ovarian cancer. However, levels can also increase due to non-cancerous conditions like endometriosis or fibroids.
Bowel cancer Though not a direct test for bowel cancer, low red blood cell counts or signs of internal bleeding in a full blood count considered alongside symptoms and health history could lead to a colonoscopy or further imaging.
Liver cancer Blood tests that check for liver enzymes or alpha-fetoprotein (AFP) levels can indicate liver inflammation or damage, which may be associated with liver cancer.
Leukaemia Leukaemia affects white blood cells. A full blood count (FBC) can detect unusual changes in your white cell levels, which might point to further checks.
These are just a few examples, and again, further tests (like biopsies or scans) are always needed for diagnosis.
What are the benefits of getting a blood test?
There are several reasons people choose to include blood testing in their health screening routine:
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Early detection – Picking up unusual trends before symptoms appear
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Peace of mind – Gaining insight into your current health status
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Tracking changes – Comparing results over time to spot patterns
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Targeted screening – Especially useful for people over 40 or with a family history of certain cancers
When blood testing is paired with other checks, such as blood pressure monitoring, body composition analysis or cardiovascular screening, it offers a more complete picture of your health.
Understand your risk
While blood tests can’t confirm or rule out cancer on their own, they can provide vital early clues that something may not be right. When combined with other checks and lifestyle awareness, they’re a valuable part of a proactive approach to managing your health.
If you’re over 40, have a family history of cancer, or simply want greater peace of mind, our Male and Female Cancer Risk packages offer targeted insights tailored to your biological sex. These include checks for key markers linked to certain cancers - such as prostate, ovarian and liver - as well as broader health indicators like inflammation, cholesterol and diabetes risk.
Your sample will be sent to a UKAS-accredited laboratory, and you’ll receive a clear, easy-to-understand Results Report, reviewed by a qualified GP. If anything needs further attention, you’ll also have free access to a 24/7 GP helpline for a full year to help guide your next steps.
Our Cancer Risk packages are available at convenient locations across the UK, making it simple to take control of your health on your terms.
Need help? Call free on
0800 652 2183 to speak to one of our team.
