TedEd: What would happen if you didn’t drink water?

A TedEd by Mia Nacamulli

Our bodies are made mostly of water. As babies, we are 75% water, which shrinks to between 55 and 60% as we grow older. Water serves to lubricate joins, regulate temperature, and nourish the brain and spinal cord. Many vital organs like the heart, brain, and lungs have high water percentages. What happens if we don't get enough of it? We lose around 3 liters a day due to sweat, urine, and bowel movements. When dehydration occurs, sensory receptor's in the brain's hypothalamus release antidiuretic hormones. In the kidneys, these create aquaporins, which allow blood to retain more water. Dehydration can cause tiredness, bad mood, lower blood pressure, and impair cognitive abilities. The opposite is over-hydration, or hyponatremia. This occurs often in athletes who drink to much. This decreases or stops output of hormones, causing sodium electrolytes to become diluted and cells to swell. In severe cases, the kidneys can't keep up with the diluted urine. This causes water intoxication, leading to headache, vomiting, and in rare cases, death. So how much is healthy? It can vary based on weight and environment, but 2.5-3.7 liters a day is recommended for men, while 2-2.7 liters is good for women. Don't forget, many of your foods also have water in them.