Can screening prevent diseases?
Screening tests are often advertised with slogans like “prevention is better than cure.” But most of them cannot influence whether someone will get ill. Many people wrongly mistake screening for “prevention,” and some think that having regular screening tests can protect them from a disease. But that is not the case: screening tests usually cannot prevent diseases. Sometimes doctors also tend to be too optimistic when it comes to the benefits of screening.
A screening program can only be considered to be a “preventive” measure if it aims to determine and influence risk factors, or detect and treat abnormal changes that could later develop into a disease. One example of this is endoscopy of the bowel, which makes it possible to detect and remove intestinal polyps that could later develop into cancer.
So preventive treatment can stop diseases from developing in some people. One disadvantage, however, is that many people then have treatment although they would never have got the disease. This is because many abnormal changes do not necessarily develop into a more serious condition, or might even go back to normal again by themselves, without causing any health problems.
Regardless of whether or not you have screening tests: if you have worrying symptoms, it is important to take them seriously and have them checked out by a doctor.