Overhydration occurs when an individual drinks too much water. When too much water is consumed, the sodium and other electrolytes that surround the cells can be diluted. This dilution causes water to seep into the cells and can cause the cells to swell. If the diluted blood reaches the brain, it could cause death. Overhydration can be a danger to those who participate in various exercises because, in an effort to stay hydrated, a person may not realize that they are drinking too much water.
In the human body, electrolytes, such as sodium, surround cells and allow efficient transfer of body communication. Osmotic pressure also maintains fluid balance in cells. When there is too much water in the body, the water can migrate into the cells to keep the osmotic pressure in balance. That extra amount of water can cause the cells to swell. This phenomenon can cause swelling of the hands and feet, one of the symptoms of overhydration.
If the diluted blood reaches the brain, it could cause brain swelling. Brain swelling can lead to the death of a person. Some of the other symptoms of overhydration are confusion, dizziness, vomiting, nausea, and reduced digestion. A person can also gain weight due to carrying too much water. Increased clear urination can also be a sign that a person is drinking too much water.
While it seems to make sense that drinking a sports drink containing electrolytes helps prevent overhydration, such drinks generally don't have the same concentration of electrolytes as the body. Drinking such beverages, therefore, may not replace the necessary sodium that the body needs to function. Instead, the water content in these drinks can help overhydration. If a person becomes overhydrated, they should stop drinking altogether so that the body can get rid of excess water.
An athlete in a marathon may not feel the need to urinate because the stress of running for long periods can promote the secretion of antidiuretic hormones. If a person is running at the time of overhydration, the runner must stop and allow the hormones to reduce in order to urinate. If excess fluid accompanies low sodium, a dose of sodium can help reduce swelling and help the body get rid of excess water. If a person thinks he is experiencing the symptoms of overhydration, especially if he is experiencing confusion, dizziness, or other neurological problems, he should seek medical attention as soon as possible.