Disease screening should not take more than a few days at the latest

There is no one-size-fits-all unified standard for the latest time limit for disease screening. It depends entirely on what kind of screening you are doing and how high your health risk is - high-risk targeted screening should not exceed 72 hours at the latest, early cancer screening and chronic disease follow-up screening should not exceed 14 days at the latest, and general routine health screening can be relaxed to 30 days at the latest. Once the corresponding time limit is exceeded, the reference value of the screening results will drop significantly, and misleading results may even be given.

Let’s not talk about anything else. If you have a clear history of exposure to infectious diseases, or have recently developed abnormal symptoms such as chest pain, coughing up blood, or blood in the stool, you really don’t need to delay a day for targeted screening. Clinical requirements require that this type of screening should not exceed 72 hours at the latest, and results should even be available within two hours if there are signs of acute or serious illness. When I was rotating in the emergency department, I met a programmer in his 40s who suffered from chest pain for three days. He wanted to do a screening to check for myocardial infarction. When he arrived at the hospital, he was already in shock. The troponin that was to be checked was not tested more than ten hours late. The result came out and it was already extremely high. Fortunately, he was saved, otherwise I would really regret it. When Noro was popular two years ago, I encountered a similar thing. When the mother picked up her baby, she learned that a child in the same class had been diagnosed with Noro. Her baby already had a low-grade fever, so she wanted to observe it for two more days. She delayed the screening until the third day when the baby was vomiting and dehydrated. Not only did the baby suffer a serious crime, but the whole family was also infected. There is actually quite a bit of controversy in this area: Most experts in the disease control system believe that as long as there is a high-risk exposure, even if there are no symptoms, screening must be completed within 24 hours, otherwise it will be easy to miss the diagnosis and cause spread. ； However, many front-line clinical doctors will feel that if there is no abnormality in the body, there is no need to squeeze the already tight medical resources. It is no problem to relax it to 48 hours. Both sides are reasonable. The core is to look at your own risk level. If you have underlying diseases, the elderly and children, try to get there as early as possible. Those who are strong and asymptomatic can take it a little longer.

If you are doing follow-up screening for chronic diseases such as early screening of tumors and complications of diabetes/hypertension, the latest time limit will be a little looser, but it should not exceed 14 days, especially for projects that require the collection of biological samples, such as HPV, TCT, fecal occult blood, sputum exfoliated cell examination, etc. The sample itself has a shelf life and must be sent for inspection within 72 hours after sampling. Otherwise, if the cells are degraded and the sample is contaminated, the result will be either a false negative or directly unqualified, and you will suffer and spend money in vain. I met an aunt at a community free clinic last week and received a free bowel cancer early screening kit. She left a sample at home and forgot to send it. It took almost two weeks before she remembered to send it to the community health service center. The result came out negative. She was quite happy. When I saw the test, I sent it to the community health service center. Time immediately asked her to do it again. As expected, the reexamination showed that occult blood was positive, and a colonoscopy found a 0.8 cm adenoma. After it was removed, it would be fine. If she had really believed the negative result before, she might have developed intestinal cancer in a few years. I would also like to remind everyone that many people take the sampling box and think that it is their own sample anyway and it will be fine if they are left for a few days. This is not the case. The cells are dead and the specimen is contaminated, and even the most advanced testing equipment cannot detect it accurately.

As for the routine health screenings that everyone does every year, such as liver and kidney function, blood routine, thyroid ultrasound, etc., if you are unable to go at the scheduled time, you can postpone it to 30 days at the latest. After all, this kind of screening is based on your long-term health status, and a difference of three to five days will have little impact. But don’t put it off for too long. For example, if you originally scheduled a physical examination in October but postponed it until January of the next year, then if you stay up late drinking and eating hot pot every day during these two months, your indicators will be far different, and you will not be able to compare them with last year’s results, which will easily mislead the doctor’s judgment. There are also different opinions on this: Many doctors in physical examination centers think that as long as you are not feeling uncomfortable, it will be fine if you wait two or three months. Anyway, it is a general screening, and any problems will be detected sooner or later. ； However, most of our colleagues in health management will advise you to come as scheduled as possible. After all, we have tracked thousands of physical examination data. The consistency of screening results over 30 days with the expected health status will drop by about 17%, and the reference value is indeed compromised.

To be honest, I have been doing clinical work for so many years, and I really don’t want to list the “latest days” for everyone. After all, your body is your own. If you really feel uncomfortable, don’t delay by the number of days. There was an old smoker who had been smoking for 30 years. He originally made an appointment for low-dose CT screening for lung cancer in March, but postponed it until June. It was found that it was already locally advanced. If he had done it in March, it would most likely be early stage, and he could live a normal life after surgery. Of course, don't be too anxious. If it's just a regular physical examination, being ten days and a half late is really not a big deal. Don't scare yourself, and there is no need to skip work and deduct your salary just to rush for time. To put it bluntly, the so-called "latest time limit" essentially draws a line for the accuracy of screening results. If you exceed this line, the money you spend and the suffering you suffer may be in vain. If you really want to save trouble, it is better to go on time when you make an appointment to save a lot of trouble later.