Can I drink water before a routine physical examination?

You can drink a small amount of water before a routine physical examination. As long as it is controlled within 200ml and no sugary or alcoholic drinks are consumed, it will basically not affect the final result. There is no need to be thirsty all morning.

Last month, I accompanied my mother for an annual physical. She coughed badly before going out and took a few sips of the honey water on the bedside table. She didn't take it seriously. The result was that her fasting blood sugar was 6.8, which was 2 points higher than last year. I was so panicked with the report that I talked to the doctor for a long time before finding out the problem with the honey water. The next day, the fasting test was repeated and it fell back to the normal level of 5.2. This pitfall of misunderstanding "you can drink a small amount of water" as "you can drink any water" has actually been stepped on by many people.

I specifically asked Nurse Zhang from the physical examination department that I often go to. She has been in this industry for almost 10 years. She said that this question is asked at least 20 times a day. It is normal for different institutions to give different answers. In order to prevent people from not controlling the amount or drinking the wrong thing, some institutions simply tell everyone "no drinking water". In fact, it is a simplified operating guideline, not an absolute medical standard. After all, the medical definition of "fasting" is not to consume calories for 8-12 hours, and there is no requirement to completely abstain from water. Ordinary cold boiled and mineral water has no calories, and drinking a small amount will not break the fasting state at all.

Of course, it depends on the situation. If you are going to do a carbon 13/14 breath test on the same day, it is best not to touch it with a sip of water. Drinking water will wash away the urea capsules in the stomach, which will directly lead to inaccurate results. To measure items such as blood lipids and liver function that are sensitive to blood concentration, try to drink as little as possible. If you are really thirsty, take a few sips to moisten your throat. Don't hold the cup and drink. Also, do not drink too much water before a routine urine test. Otherwise, the urine will be over-diluted. Slight urinary protein and urinary occult blood problems may be "hidden", which will delay the discovery of the problem. I have previously encountered a young woman who had a gynecological B-ultrasound and drank two large bottles of mineral water before the blood was drawn in order to hold her urine quickly. As a result, the urine routine results were all borderline, and she had to retake the test another day.

There is also a group of physicians who have a more cautious view. They feel that if you are doing physical examinations that require extremely high results such as entry and school, or if you have liver disease or dyslipidemia and need to review the indicators, it is best not to drink water at all to avoid even a one-ten thousandth deviation. This consideration is completely reasonable. After all, everyone's metabolic rate is different. It is true that drinking 100ml of water will cause slight fluctuations in blood concentration.

There is another special situation that many people ignore: if you have chronic diseases such as high blood pressure and diabetes that require long-term morning medication, you do not need to stop taking the medicine for a physical examination. Just drink a small amount of water and take the medicine.

If you are really not sure, just put a small bottle of plain water in your bag. After the blood draw, abdominal B-ultrasound and breath test are completed, no one will care about how much you drink. You can't break the rule of being so thirsty that your throat will smoke all morning, right?