In this blog post, we will take a closer look at why excessive water intake can be harmful to your health, focusing on the risks such as hyponatremia.
What happened to A?
A, who learned that the secret to maintaining the firm skin of people with firm skin is to “drink enough water,” decided to drink a lot of water from that day on. A drank 1L of water every day, but she didn’t notice much change in her skin. She wanted to have firm skin as soon as possible, so she gradually increased the amount of water she drank. However, her body began to undergo some unexpected changes. She felt fatigued more easily than before, and sometimes felt as if her muscles were cramping. She also complained of nausea and severe headaches. Eventually, she collapsed and was taken to the emergency room in an unconscious state. There, she was diagnosed with hyponatremia.
Hyponatremia! The cause is an excess of water intake
The basic structural and functional unit of the human body is the cell. Water exists in the inner and outer spaces of the cell, and the cell membrane separates the two spaces. Water accounts for about 60% of a human’s body weight, and one-third of the water in the body is in the form of extracellular fluid and two-thirds is in the form of intracellular fluid. The cell membrane is composed of a phospholipid bilayer that restricts the movement of polar molecules. Water molecules, on the other hand, are polar molecules but are small enough to pass through the cell membrane freely. If there is an osmotic concentration difference between the inside and outside of the cell, water molecules move in the direction that eliminates the osmotic concentration difference, keeping the osmotic concentration of the two spaces the same.
Consider the situation of putting cabbage in salty water. At this time, the osmotic concentration of the extracellular fluid increases. This is because the external environment affects the extracellular fluid first, not the intracellular fluid. Osmotic concentration refers to the solute concentration of molecules and ions that determine the magnitude of osmotic pressure. The most significant factors affecting the osmotic concentration in cells are sodium ions (Na⁺) and chloride ions (Cl⁻). To explain the osmotic concentration simply, it can be said that it indicates the degree of saltiness of the salt solution. A solution with a high osmotic concentration is a salty salt solution, and a solution with a low osmotic concentration is a bland salt solution. The chemical formula of salt is NaCl, and when NaCl is dissolved in water, it acts as an ion that determines osmotic pressure.
Let’s understand osmotic concentration with the following example. Suppose a container is divided into two parts by a semi-permeable membrane. This semi-permeable membrane does not allow the salt, which is a solute, to pass through, but it does allow water to pass through. This is similar to the function of a cell membrane. Let’s assume that 100 g of salt is added to 1 L of water in the left compartment and 1 g of salt is added to 1 L of water in the right compartment. At this time, it is assumed that the volume of both compartments is the same. Which compartment’s brine is saltier? Obviously, it is the left compartment. Therefore, it can be said that the osmotic concentration of the left compartment is higher.
The reaction continues until the osmotic concentration reaches equilibrium, where the concentration of salt and water is equal. If there were no semipermeable membrane, the salt in the left compartment would move to the right compartment and the water in the right compartment would move to the left compartment, eventually reaching equilibrium. However, with the semipermeable membrane, the salt particles cannot move to the other compartment. This is because a semipermeable membrane selectively allows substances to pass through it. Salt particles cannot pass through the membrane, but water molecules are small in size and can freely pass through the semipermeable membrane. Therefore, in order for the osmotic concentrations of the two spaces to be equal, more water from the right compartment will move to the left compartment. As a result, there will be more water in the left compartment than in the right compartment.
Why is there more water in the left compartment? This is to make the salt water concentration in the two compartments the same. If there is 100g of salt in the left compartment and 1g of salt in the right compartment, you would use 2L of water to make the concentration of the two compartments the same. At this time, more water must be added to the left compartment to make the salt water concentrations of the two compartments equal. This is the principle that when a semi-permeable membrane is present, a greater amount of water will be present in the left compartment in an equilibrium state.
Now, let’s go back to A’s story. So far, we’ve been talking about salt, but it is actually sodium ions that play an important role in regulating osmotic concentration in the body. A’s excessive intake of water resulted in an excessively low osmotic concentration of extracellular fluid. As the osmotic concentration outside the cell decreased, water flowed into the cell, causing the cell to swell.
Hyponatremia is a condition in which a large amount of water flows into cells due to a difference in osmotic concentration, preventing the cells from functioning normally. Brain cells are particularly vulnerable to damage when excess water flows into them. The brain is located inside the hard skull, which puts pressure on the brain cells when they swell. This is like loose pants becoming tight due to weight gain. When brain cells are compressed, they can be severely damaged, which is why A felt dizzy and had a headache, and eventually fell unconscious.
Treating hyponatremia by reversing the cause of the disease
The cause of hyponatremia is that the osmotic concentration of extracellular fluid drops sharply, causing an excessive amount of water to flow into the cell, causing the cell to swell and lose its function. Cells must maintain a certain size and osmotic pressure to function normally, and if the water imbalance causes the cell to swell abnormally, various functions will be impaired. The brain is the most sensitive organ to this. Brain cells are trapped in the skull, which unlike other cells, lacks the space to expand, so brain damage is accelerated when the brain is pressurized by excess water. For this reason, people with hyponatremia may experience dizziness, headaches, and even coma.
This disease is caused by a difference in osmotic concentration, so it can be treated by using this in reverse. In order to normalize the situation where the osmotic pressure is imbalanced, the osmotic concentration of the extracellular fluid must be restored using isotonic solution. Isotonic solution is a solution with the same osmotic pressure inside and outside the cell, which is the same as the natural osmotic pressure of the human body. When isotonic solution is injected into the blood vessels, the osmotic concentration of the extracellular fluid gradually recovers, and the excess water that has flowed into the cells is released back into the extracellular fluid. In this process, the volume of the cells returns to normal, and the swollen cells regain their function.
This treatment is very important, especially in cases of hyponatremia, where rapid treatment is essential. This is because irreversible damage can occur when brain cells are under pressure for a long period of time. Isotonic fluid administration is a key treatment to reduce this risk. The effects of isotonic fluid administration go beyond simply controlling the size of cells. When the osmotic concentration of extracellular fluid is normalized, the body’s overall water balance is restored, allowing other organs and tissues to function smoothly. The permeability of the cell membrane is also normalized, restoring the normal functioning of the nervous and muscular systems.
In some cases, it is possible to restore the osmotic concentration of extracellular fluid more quickly by using isotonic fluid in addition to isotonic fluid. Hypertonic saline is a solution with a concentration higher than the osmotic concentration in the body, and when administered, the movement of water to the outside of the cell is faster. However, if hypertonic saline is used excessively, it can cause dehydration by excessively removing water from the cells, so it is used under the careful judgment of a specialist.
Another important factor in the treatment of hyponatremia is limiting fluid intake. If you drink an excessive amount of water, such as in the case of A, the situation will worsen if you drink more water before your body naturally excretes water. Therefore, patients with hyponatremia are restricted from drinking water for a certain period of time. This is a measure to normalize the water concentration in the body and restore the balance between extracellular fluid and intracellular fluid.
Ultimately, hyponatremia is caused by excessive water intake, but the way to correct it is also to control the movement of water. Treatment using isotonic or hypertonic solutions is based on this principle and focuses on restoring the normal osmotic concentration of cells. This restores the water balance inside and outside the cell and quickly relieves the patient’s symptoms.
Excessive water intake is harmful
Water plays an essential role in the body’s energy metabolism, but excessive water intake can be dangerous. Water plays a variety of roles in the body, including regulating body temperature, excreting waste, and transporting nutrients, as well as in the body’s metabolic processes. However, no matter how important water is, excessive intake can be harmful to health. In particular, drinking excessive water while the body’s water metabolism is not functioning properly can cause diseases such as hyponatremia as the osmotic concentration of extracellular fluid drops sharply.
Our bodies have the ability to regulate water intake to maintain a balance of fluids. The kidneys play an important role in this process, and excess water that is not needed by the body is excreted in the urine through the kidneys. However, drinking too much water in a short period of time can cause the kidneys to not process it sufficiently, resulting in an imbalance of fluids. The kidneys can process about 800 mL to 1 L of water per hour, and if you drink more than this amount, your body’s balance begins to break down. At this time, excess water accumulates in the body, causing changes in the osmotic pressure inside and outside the cells, and excessive water flows into the cells, causing them to swell.
In particular, the problem in this process is the dilution of sodium concentration. Sodium is essential for maintaining electrolyte balance in body fluids and regulating nerve and muscle functions. However, if you drink too much water, sodium may become relatively deficient, causing hyponatremia. Hyponatremia is a condition in which the sodium concentration in body fluids is excessively low, causing abnormalities in various bodily functions. In mild cases, symptoms such as headache or nausea may occur, but in severe cases, it can lead to coma or death.
In addition, drinking too much water can cause brain swelling. Unlike other parts of the body, the brain is surrounded by a hard skull, so it has little room to expand. When excess water flows into brain cells, the brain swells, increasing the pressure inside the skull, which causes headaches, dizziness, vomiting, and visual disturbances. In severe cases, it can lead to neurological symptoms such as decreased consciousness, and prolonged exposure to this condition increases the risk of brain damage.
Another problem is the strain on the heart. Excessive fluid intake increases blood volume, which means the heart has to pump more blood. The heart works harder to supply this additional blood to the entire body, which can put a strain on the heart in the long run and increase the risk of cardiovascular disease.
Therefore, drinking the right amount of water is the most important thing. The recommended daily water intake for adults is generally around 2-2.5 liters, which may vary depending on an individual’s activity level, weight, climate, etc. However, drinking significantly more than this amount should be avoided. In particular, drinking a large amount of water in a short period of time can put a heavy burden on the kidneys and the body’s water regulation system, which can have adverse health effects.
In addition, you should consider your physical condition to balance your water intake. If you are not properly excreting water or have a specific disease, you should adjust your water intake more carefully. For example, patients with heart failure, liver disease, and kidney failure cannot excrete water efficiently, so excessive water intake can be dangerous. Therefore, it is essential for people with these diseases to control their fluid intake according to the advice of their doctor.
In conclusion, water is essential for maintaining good health, but it is important to remember that drinking too much can actually be harmful. As with everything, it is best to drink water in moderation. Rather than drinking too much water simply because it is important to drink water, it is important to drink the right amount for your body and listen to your body’s signals to regulate your water intake.
