Water is essential to good health
1/16/2025 by Denise Dupras, M.D., Ph.D.
Water makes up between 50% and 70% of your body weight. It's essential for every cell, tissue and organ in your body. Water removes waste through urination, perspiration and bowel movements. It's also a component of the lubrication and cushioning of your joints and helps to regulate your temperature.
How much water you need depends on several factors:
- Environment: You may need more water at higher altitudes or in hot or humid weather.
- Exercise: If you sweat, you need to replace the water. Sometimes, you may need to include rehydration fluids to add the salt you lose with excessive perspiration back into your body — especially in hot weather.
- Illness: Vomiting or diarrhea increases the loss of water.
- Pregnancy and breastfeeding: You may need additional fluids.
- Medications: If you take a diuretic, you may need to manage your fluid intake under the supervision of your healthcare team.
Without enough water, you can become dehydrated. Symptoms of dehydration can include feeling dizzy or lightheaded, tired, fatigued or having a headache. You can avoid dehydration by drinking water — and water from the faucet is just fine. Other fluids such as milk, juice and herbal teas can replace some of your water intake. And yes, even coffee and soda, but be careful of sugar-based drinks as they add calories. You can infuse water with flavor using herbs, fruits and vegetables. Don’t forget that some fruits, like watermelon, are almost all water.
So, how do you know if you are drinking enough? If your urine is light yellow or clear and you don’t feel thirsty, you are likely drinking enough. If you have questions, consulting your healthcare team is always a good idea.
You can also drink too much water. This can lead to problems with the levels of sodium in your blood, and that is dangerous. Excessive thirst can also be a symptom of diabetes. So, if you have a thirst that cannot be quenched, pay attention and contact your healthcare team.
Denise Dupras, M.D., Ph.D., is a general internist in the Division of Community Internal Medicine, Geriatrics and Palliative Care. She completed her medical and doctoral degrees at Mayo Clinic Alix School of Medicine and her residency in internal medicine at Mayo Clinic in Rochester. Her interests include medical education and LGBTI medicine.