Drinking 8 glasses of water a day almost made me blind! How to drink water healthily?

Reviewer: Wu Xinsheng

Deputy Chief Physician, Department of Gastroenterology

I believe everyone has heard that "eight glasses of water a day is good for health". However, a lady in Changsha felt eye pain, dizziness and nausea after drinking a lot of water in a short period of time. The hospital diagnosed that Ms. Liu suffered from acute angle-closure glaucoma. What's going on?

Source: Internet

Experts explained that the woman suffered from this disease mainly because she was susceptible to glaucoma, and drinking a lot of water at one time was just the trigger. After drinking a lot of water, the blood in the human body is diluted and the plasma osmotic pressure is reduced, which causes the eyeball to quickly produce a large amount of aqueous humor, causing the intraocular pressure to rise instantly. Ordinary people can regulate intraocular pressure through their own metabolism, but for people at high risk of glaucoma, their ability to regulate intraocular pressure is poor and they cannot eliminate excess aqueous humor in time. Drinking too much water at one time may increase intraocular pressure and cause the disease.

Source | Screenshot from Weibo @大米Video

How to determine if you are dehydrated?

Ordinary people's eyes will not be affected by drinking too much water. Generally speaking, as long as you drink "small amounts and multiple times" and your body is not dehydrated, it will be fine. So, how do you judge whether you need to drink water?

First of all, if you feel dry mouth, you need to drink water in time.

Source: pixabay

Secondly, you can judge by urine. After a full night's sleep, if our first urine is yellow and has a strong odor, we can conclude that we are not drinking enough water. If the body is well hydrated, the urine will have no odor and will be colorless.

Third, we can also judge whether the body is dehydrated by bowel movements. If you have at least one bowel movement a day, it means that the body is well hydrated. Because drinking water can keep your intestines nice and smooth and move the waste in the intestines in the right direction.

Fourth, when your eyes are bloodshot, dry, and generally uncomfortable, it may also mean that your body needs water to moisturize your eyes.

There are misunderstandings about drinking water. Have you made any mistakes?

In recent years, there are more and more "tips" about drinking water on the Internet, but many of them have no scientific basis. The editor below summarizes several common misunderstandings about drinking water. Let's take a look.

Myth 1: Drink water only when you are thirsty

In fact, feeling thirsty is already a clear sign of dehydration, so you shouldn’t wait until you feel thirsty to drink water. When the body fluid consumption is about 1% of body weight, the body will feel thirsty, the plasma osmotic pressure will increase, and the ability to move will be affected.

Source: pixabay

When it reaches 2%-4%, the human body is already in a state of dehydration. When you feel thirsty, your urine will decrease. The color of your urine is not the normal slightly yellow, transparent or white, but dark yellow. The specific gravity of urine will also increase. At this time, our working ability and cognitive ability will be reduced. When it reaches 4%~8%, the human body is already in a state of moderate dehydration. At this time, symptoms such as dry and inelastic skin, chapped mouth and tongue, hoarseness, rapid heart rate, and irritability will appear. In severe cases, it will cause a drop in blood pressure and even endanger life. So don't wait until you are thirsty to drink water. You should take the initiative to drink water regularly, about 200 ml each time.

Myth 2: Drink a glass of salt water in the morning

Some people believe that drinking a glass of light salt water after getting up early can expel toxins accumulated in the body and promote kidney circulation. However, the daily salt intake of Chinese residents is already excessive, so adding salt to water will only increase the burden on the body. Drinking less alcohol, not consuming excessive salt, and staying up late are the real "detoxification". The human body is not a flush toilet, so how can you "flush" the so-called toxins out of the body just by drinking a glass of water?

In addition, the body will have some hidden sweating and urine secretion during long sleep, which will cause the loss of water in the body. Therefore, although you may not feel thirsty when you get up, the blood will still be viscous due to lack of water. Therefore, you can drink some pure water on an empty stomach in the morning to reduce blood viscosity and increase circulating blood volume.

Myth 3: Drink more hot water

Many people in today's society believe that "drinking more hot water" is a healthy lifestyle, but studies have shown that hot drinks above 65°C may cause cancer. This is because our esophageal mucosa is very fragile, and water that is too hot can easily cause scalding of the esophageal mucosa. What's more dangerous is that the esophagus is not sensitive to temperature, and even if it is scalded, we don't feel anything. Therefore, drinking hot water frequently is a chronic stimulation to the esophageal mucosa. The damage has not been repaired, and new trauma has occurred. In the long run, it will increase the risk of cancer. For the delicate esophagus, water between 10°C and 40°C is the most suitable. Hot water above 65°C will cause scalding, so don't be impatient whether drinking water or eating.

Source: Internet

Myth 4: Drinking boiled water is harmful to health

Many people believe that water that has been repeatedly boiled contains a large amount of nitrite, which may cause cancer. In fact, according to People's Daily, the nitrite content in water does increase after it is heated many times, but the increase is very small. Therefore, even if the water is heated many times, the nitrite content is very low and is safe.

Nitrite content trend chart in the experiment/screenshot from the program "Is it true?"

Myth 5: You can use milk and juice instead of water

Nowadays, many young people believe that juice and milk not only contain water but also contain more vitamins and proteins. Using them instead of water can replenish water and nutrition at the same time, killing two birds with one stone. In fact, this is not the case. First of all, juice contains a lot of sugar. Using juice instead of water can easily cause the body to consume excessive sugar and lead to obesity.

Source: pixabay

Secondly, fruit juice usually contains additives, which can have adverse effects on the stomach. Milk contains more protein, and drinking a lot of it will increase the burden on the liver and kidneys. Therefore, you should still drink water normally in your daily life and try not to replace it with other drinks.

Correct posture for drinking water

1. It is best to drink warm water: cold drinks may cause gastrointestinal discomfort or even diarrhea; boiling water can damage the esophageal mucosa and stimulate mucosal hyperplasia, thereby inducing esophageal cancer. Therefore, the most suitable temperature for drinking water is 10℃-30℃.

2. Don’t drink water in big gulps: Many people like to drink water in big gulps when they are thirsty, but they don’t know that this is wrong. The correct way to drink water is to take a sip of water and swallow it slowly in multiple times.

3. The amount of water you drink varies from person to person: Many people like to set a limit on how much water they should drink every day, but this is actually not necessary. Healthy people can judge whether they need to drink more water by the color of their urine: normal urine color should be light yellow. If the color is too dark, you should drink more water; if the color is very light, you may have drunk too much water.

Source: pixabay

4. Pay attention to the time after opening the bottled water: In addition, many families are accustomed to drinking bottled water, thinking that this is clean and hygienic. However, if the bottled water is opened for a long time, bacteria will slip in through the water inlet. If it is not drunk in a short period of time, the bacteria in the water will exceed the standard and the purified water will no longer be pure.

It can be seen that drinking water is also a science. It is recommended that everyone should develop good habits and drink water regularly, in small amounts and multiple times.