There is such a story on the Internet that if you drink some water before taking blood for analysis, the blood will become liquid, and the concentration of something there will decrease. And the analysis will turn out to be wrong. This is nonsense.
The same nonsense as about the clotting of blood from the fact that you drank one glass of water less yesterday.
No, it doesn't work that way. It would be too easy. We would drink our own water and dilute the thick blood. But that won't work.
Heavy water
Let's start simple. If we drink water, then within 5 minutes a noticeable amount of this water will be in the blood. How was it measured? Simple and rude. They gave people not ordinary water, but a mixture with heavy water. Remember heavy water? An atomic bomb, a nuclear reactor, all that... There, instead of hydrogen, its isotope is deuterium. Such water is not radioactive, but it can be detected by instruments.
A person will die only if he replaces a quarter of all water with heavy water. So you can experiment widely. And so scientists gave people some heavy water and checked how quickly this water will appear in the blood. In 20 minutes it was already the maximum.
Where will the water go
The water we drink will go into the blood, inside the cells, into the intercellular space, excreted by the kidneys and various glands in our body. On average, this process is so balanced that it is very difficult to thicken or dilute your blood. Hence the rule - drink as much water before the blood test as you like.
Do you understand?
A blood test should show what is relevant to you. There is no standard water consumption. You may be sweating or chronically eating salty, or you have diabetes. It does not matter. The analysis should show exactly what is characteristic for you personally. So let your blood be diluted or concentrated as you like. You can drink water. But you usually don't need to drink any soda or jelly before a blood test.
Home pregnancy test
It seems to me that I figured out where this story about water limitation came from before the analysis. This is done before home pregnancy test.
There, the test should reveal a certain concentration of the hormone chorionic gonadotropin. If you drink too much water, then this excess water will not be in the blood. But this excess water will be in the urine and dilute the hormone concentration. The test can give a false negative result. Got it?
The kidneys regulate the amount of water in the blood so that the blood will always be the same. But the amount of water in the urine will vary widely.
We even suggest that people use their urine to assess themselves for signs of dehydration. If the urine becomes dark and concentrated, then this is a sign that there is not enough water in the body, and the kidneys do not allow it to go into the urine. Conversely, if the urine is light like water, then this is a sign that there is a lot of water in the body, and the kidneys are draining excess water.
Briefly speaking
Before taking blood for analysis, you usually cannot eat or drink tea with sugar, but you can drink plain water. This water will not affect the analysis, and if it does, it will just be the result of the analyzes.
It is better to do a home pregnancy test from the first morning urine and do not drink water before that, so as not to dilute hormones in the urine.
Read my articles on the links in the text. There is a lot of useful information.
And you were not prohibited from drinking water before the blood test?
