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Non-invasive testing describes medical testing that does not involve physically entering the body or skin. Most tests that are performed at a routine physical check-up are non-invasive. The most common of these tests are blood pressure monitoring, chest exams using a stethoscope, and x-rays and other types of scans.
Non-invasive testing is just one type of testing doctors can use to diagnose problems occurring in the body. These tests are limited in scope but will generally be the first choice when available because they are easier on the patients and involve much less risk. Semi-invasive or minimally invasive testing is another type of test that describes blood testing or even colonoscopies where a needle or tube is inserted in the body. Invasive testing usually describes surgery and is the last resort for doctors when diagnosing a problem.
X-rays, CT scans, and other types of scans are great examples of non-invasive testing. This technology uses radio waves that actually move through the body and can provide doctors with pictures of the inside of the body. This type of test is qualified as non-invasive because, though it provides a picture of the inside of the body, it doesn't involve any invasive cutting.
Most of the testing done during a routine physical examination is considered non-invasive. Visual tests are non-invasive, as they require only observation and do not involve entering the body. The doctor may shine a light inside the ears, nose, and throat to get a better picture of any inflammation or other problems going on inside the body. A stethoscope may likewise be used to listen to the heart and lungs to make sure they are functioning properly. All of these tests are considered non-invasive because they do not breach the natural boundaries of the body, such as the skin.
There is quite a bit of controversy in the medical field surrounding non-invasive testing versus more traditional tests. This is particularly true when it comes to methods of testing for heart problems, such as arterial blood clots. Many traditional doctors rely on cardiac catheterization, a very invasive type of surgical diagnostic method, to diagnose and then treat blood clots in the arteries. These doctors argue that cardiac catheterization is the most accurate way to find blood clots, and because surgery is already in progress, the clots can be treated right then and there.
Advocates of non-invasive testing for heart disease argue that these traditional doctors are missing the point of the tests. Cardiac catheterization can only detect discrete blockages when they are present, whereas CT scanning can actually find underlying causes of the blockages before they become blockages and potentially heart attacks. Many heart attacks are caused by prolonged narrowing of the arteries, which is better detected from CT scanning than invasive cardiac catheterization.