Screening vs. diagnostic testing: what’s the difference?

July 15, 2022

We often hear about medical tests that screen for disease and cancer, such as regular mammograms for breast cancer screening and Pap Smears for cervical cancer. On the other hand, there are medical tests that help doctors diagnose conditions, such as biopsies and blood tests. But how exactly do these tests differ? Let’s dive into the differences between screening and diagnostic tests.

What is a screening test?

A screening test is often done to detect potential health disorders or diseases in people who do not have symptoms of disease. There are 2 main goals of screening tests:

  1. Early detection. When diseases are detected early, treatment is often more effective and successful.
  2. Monitor potential risks for certain diseases. By catching signs of developing diseases early, lifestyle changes can be made to reduce the risk.

Screening tests are particularly beneficial for those who are asymptomatic but pose a higher risk of developing disease. Screening may lead to the need for a diagnostic test to determine whether or not a patient has a certain disease.

What is a diagnostic test?

A diagnostic test is often used to investigate a specific concern to determine the presence or absence of disease. It is often used to diagnose conditions in patients that display symptoms or asymptomatic patients with a positive screening test. Diagnostic tests allow doctors to create effective treatment plans so patients can recover quickly and with the least amount of complications.

What’s the difference between screening and diagnostic tests?

The main difference between a screening and diagnostic test is the purpose of the test. Screening tests are primarily used for early detection of disease or risk factors whereas diagnostic tests are used to establish the presence or absence of disease. Screening tests are often done among people without symptoms who may have a higher risk of developing disease. At Prenuvo, our MRI scans are screening tests for those who wish to detect diseases early.  Prenuvo members may choose to get their MRI scans because they have a higher risk or genetic propensity for disease, though other members simply want the most advanced preventive care available regardless of their risk factors. We strongly believe in the benefits of proactive healthcare and our screening tests can identify signs of cancer and other diseases earlier to enable more effective and less invasive treatments.

On the other hand, diagnostic tests are often done among people that display symptoms of disease or asymptomatic individuals with a positive screening test.

The results of a screening test indicates a high or low probability of disease whereas the result of a diagnostic test is more likely to provide a definite diagnosis.


Examples of screening and diagnostic tests

There are a range of screening and diagnostic tests used for specific medical conditions. Healthcare providers advise on the recommended tests for individuals, as well as the frequency and timing of these tests.

Screening Tests


Many health organizations worldwide recommend regular mammography screening for breast cancer, particularly for women aged 50 to 74. Mammograms are done in a clinic or screening center by a radiology technologist who will position the breast on a special x-ray machine. For many women, mammograms are the best way to detect breast cancer early, when treatment is more effective and successful.


A colonoscopy is a procedure used to screen for colon cancer among those who pose a high risk of developing colon cancer, such as individuals with a family history of colon cancer. The procedure involves inserting a flexible tube with a tiny camera attached to examine the inside lining of the rectum and colon. During the test, the doctor can find and remove most polyps and some cancers. If colon cancer is detected at its earliest stage, the chance of survival is more than 90%.

Prenuvo MRI Scan

In today’s health-conscious society, people are taking steps to be more proactive, as opposed to being reactive, with their health. Getting a Prenuvo whole-body MRI scan provides you with a comprehensive overview of your health, telling you what’s going on inside your body that you may not have known otherwise. A Prenuvo scan assesses your body and can detect over 500 medical conditions, including cancer, spinal degeneration and fatty liver disease. Early detection allows for more effective treatment and ultimately, better health outcomes. By obtaining a comprehensive health profile, you’re able to recognize abnormalities, monitor changes within your body and see how incorporating certain lifestyle choices can impact your general health and wellbeing.

Diagnostic Tests


A biopsy involves taking a small piece of tissue from the body to be examined and checked for damage or disease. It can be done on all parts of the body. Usually, they are done to check whether or not a lump is cancerous.

Laboratory Tests

If you’ve had a routine medical check-up, you most likely have had a laboratory test. This common diagnostic test involves gathering a sample of your blood, urine or body tissue to be analyzed by laboratory technicians to see if your results fall within the normal range. It helps doctors diagnose medical conditions, plan or evaluate treatment and monitor diseases.


The procedure often done to investigate issues in the abdomen or a woman’s reproductive system is called laparoscopy. This type of surgery involves inserting a thin tube called a laparoscope into the abdomen through a small incision in the skin. The tube has a camera attached to send images to a video monitor, allowing the surgeon to view inside the body without major trauma to the patient. Laparoscopic surgery may be used to diagnose tumors, blockages, unexplained bleeding and infection in patients experiencing abdominal symptoms. For women, it can also be used to diagnose and/or treat conditions such as endometriosis and pelvic prolapse.

Putting it altogether

Screening tests are not diagnostic tests, yet both have an important place in the spectrum of medical care. Screening tests are completed for people who do not exhibit symptoms of disease, whereas diagnostic tests are completed for people who do exhibit symptoms. At Prenuvo, we have screened tens of thousands of members to help them gain detailed insights into their health. Contact our team today for more information on the benefits of proactive health screening.

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