Is it normal for disease screening tests to be negative?

In most cases, it is normal and a good thing that the disease screening results are all negative, which means that at this point in time of sampling, you do not suffer from the diseases covered by this batch of screening projects.

However, don’t take this result as a guarantee that you are “disease-free”. There are indeed many special circumstances in clinical practice that can make negative results “watery”. I encountered such a thing when I was rotating in the laboratory department of a hospital two years ago. A young man in his early 20s came to get tested for HIV in a hurry three days after he had had high-risk sexual behavior. After receiving the negative report, he turned around and was about to go to the next appointment. I quickly stopped him and told him that it was still in the window period, and the virus It has not reproduced in the body to a detectable amount, so the result does not count. He has to wait 4 weeks before taking the test again. He was still dubious at the time, but when he came back for a re-examination in the 5th week, he was indeed found to be positive. Fortunately, he warned him too much at the time, which prevented him from inadvertently infecting other people.

In addition to the limitations of the window period test itself, another very common problem is the limited coverage of screening. Just like you can only catch crucian carp with a net, you will definitely not be able to catch carp. Routine health screening generally only covers common infectious diseases such as hepatitis B, hepatitis C, AIDS, and syphilis, as well as basic items such as chest X-ray, blood routine, and liver and kidney function. If you are the most If you have a cough with yellow sputum and a low fever in the afternoon, even if the chest X-ray result of a routine physical examination is negative, you should take the initiative to tell the doctor about your symptoms and do a follow-up tuberculin test or chest CT. Don't rely on the negative results of routine screening, which will delay the condition.

There are two extreme views on the Internet now. One is that a positive screening test means that you are 100% healthy, and you will not go to the hospital even if you feel uncomfortable. The other is that you are anxious every day after getting a negative result, wondering if there is some rare disease that has not been detected. Both of these ideas are actually a bit biased.

If you don’t have any discomfort or special exposure history, and you just go for annual physical examination or job entrance screening regularly, then you can rest assured and do what you should do. There is no need to dwell on such small probability events as "will the test be missed", which may lead to anxiety attacks. But if you do have a clear history of high-risk exposure, or have already developed corresponding symptoms, even if the current screening result is negative, you must follow the doctor's instructions for reexamination on time, or add more accurate testing items.

To put it bluntly, the screening itself is a "preliminary screening" and is not a final diagnosis. Whether the result is yin or yang must be judged based on your own actual situation. You don't need to take it too seriously, and don't take it seriously at all.