Why is it said that drinking water before bedtime to reduce blood viscosity cannot reduce the incidence of nocturnal blood clots?

Someone told Huazi that he wanted to reduce blood viscosity and prevent blood clots, so he drank a large glass of water every night. But after drinking the water, he always had to get up at night to urinate, which affected his sleep. But he didn't dare not drink it, which was very distressing. Huazi told him that it was actually not necessary to drink so much water before going to bed, because drinking water before going to bed, although it can reduce blood viscosity, it cannot reduce the incidence of nighttime blood clots.

1. People lose water when they sleep When people sleep, they lose water in their bodies through breathing, sweating, and the formation of urine. Based on 8 hours of sleep, the human body will lose about 500 ml of water. Some people believe that water loss will cause the blood to concentrate and become more viscous, which will lead to the formation of blood clots. Therefore, drinking water before going to bed and replenishing the lost water in advance can prevent blood clots.

But in fact, the water lost during sleep has little effect on blood viscosity. Because 60% of the human body is water, a 120-pound adult has 72 pounds of water in the body. Most of the water is not in the blood, but in various tissues. People lose about 1 pound of water during sleep, which is the amount of water lost by the blood and various tissues. It has very little effect on the blood and will not cause serious blood concentration.

2. Blood viscosity has little to do with thrombosis. In relevant studies, blood viscosity is not the main factor causing thrombosis. Even if a healthy person is very thirsty or even dehydrated, the blood in the blood vessels will still flow normally and will not cause thrombosis. The cause of thrombosis is atherosclerosis in the arteries, and the hardened plaques continue to grow and block the blood vessels; or the surface of the hardened plaques ruptures, inducing platelet aggregation, which will lead to the formation of thrombosis.

The reason why myocardial infarction and cerebral infarction are prone to occur at night is because of changes in blood pressure. The human body's blood pressure drops at night and rises sharply in the early morning, which can easily induce arterial spasm, leading to plaque rupture and thrombosis. It has nothing to do with the viscosity of the blood.

3. How to prevent thrombosis? To prevent thrombosis, we need to find ways to stop the progression and rupture of atherosclerotic plaques. The progression of plaques is the result of multiple factors that damage the arterial intima. The main factors are high blood pressure, high blood lipids, high blood sugar, smoking, etc. Therefore, to prevent the progression of plaques, you need to quit smoking and limit alcohol, maintain good living habits, and control chronic diseases. Keep blood pressure below 140/90mmHg and fasting blood sugar below 7mmol/L.

Different targets are set for blood lipid control according to different risks. For people who only suffer from the "three highs" chronic diseases but have not suffered from cerebral infarction, myocardial infarction, or coronary heart disease, the low-density lipoprotein cholesterol (LDL-C) in blood lipids should be controlled at 2.6mmol/L; for people who have suffered from the above diseases, to prevent recurrence, LDL-C should be controlled below 1.8mmol/L; for people with extremely serious risks, LDL-C can be controlled below 1.4mmol/L.

To prevent plaques from rupturing, a healthy lifestyle is the basis, such as eating less salt, less fat, less sugar, and more exercise. At the same time, taking statins can "reinforce" the plaques while controlling blood lipids, increasing the density of the plaques, reducing their size, and making them less likely to rupture.

For people with a high risk of plaque rupture, antiplatelet therapy is also required. For example, taking aspirin can inhibit platelet aggregation. In this way, when the plaque ruptures, platelet aggregation can be prevented and blood clots can be avoided. However, before taking the medicine, it is necessary to be evaluated by a doctor to determine that the benefits of taking the medicine outweigh the risks.

To sum up, drinking water before going to bed does not prevent blood clots. Drinking too much water will cause frequent urination, affecting sleep. Poor sleep will increase blood pressure, which will increase the incidence of blood clots. So you don't have to drink more water before going to bed. You don't have to drink if you are not thirsty. Pay attention to controlling the "three highs" and taking medicine regularly is the correct way to prevent blood clots. I am pharmacist Huazi, welcome to follow me and share more health knowledge.