What should you know about hydration?

About 50-75% of your weight is water! Getting enough fluid in your diet is important for everything in your body to work well and be healthy, including your heart, digestion, brain, muscles and skin. Fluids deliver nutrients to your cells, maintain a balance of nutrients, and remove wastes from your body. Good hydration supports normal energy levels, decreases risk of kidney stones, prevents constipation, and is associated with a reduction in urinary tract infections, high blood pressure, fatal heart disease and stroke.

Fluids can come from a variety of sources including water, milk, 100% fruit juice, tea, coffee. Alcohol, particularly in large amounts, can cause the body to get rid of more fluid; so if you drink, do so in moderation. Avoiding large amounts of caffeinated beverages can also help you stay well hydrated. It is estimated that foods provide about 20% of our water intake. Including plenty of water-rich fruits and vegetables can be a good source of fluids. Replacing sugar-sweetened beverages, whole milk, and juice with water is a healthy choice that can support weight loss by reducing calorie intake.

Most people maintain adequate hydration by consuming liquids at meals and drinking when thirsty. The amount of fluid one needs can vary based on body size, temperature, physical activity, diet, medical conditions and illnesses.

What are some signs of dehydration?

Some signs of dehydration include:

Those at particular risk for dehydration

  • Older adults are at particular risk for dehydration, particularly in warmer weather or when sweating a lot. Older adults are not as sensitive to feeling thirsty so must be mindful of consuming fluids throughout the day.
  • Athletes and avid exercisers are also at risk for dehydration and must be mindful to drink before, during and after exercise to prevent dehydration.
  • Illness can lead to dehydration. Adults should consult a doctor if vomiting occurs for more than one day, if diarrhea and vomiting last more than 24 hours, and if there are signs of dehydration.

Some people with certain health conditions such as heart, kidney, and liver disease may require restrictions on fluids. If you have medical conditions, consult with your physician for advice on proper hydration.

Last reviewed by a Cleveland Clinic medical professional on 05/10/2019.


  • Centers for Disease Control and Prevention. Water and Nutrition. (https://www.cdc.gov/healthywater/drinking/nutrition/index.html) Accessed 5/17/2019
  • Exercise and Fluid Replacement Medicine & Science in Sports & Exercise: February 2007 - Volume 39 - Issue 2 - p 377-390 (https://journals.lww.com/acsm-msse/toc/2007/02000)
  • National Academies of Sciences, Engineering, and Medicine. Dietary Reference Intakes: Water, Potassium, Sodium, Chloride, and Sulfate. (http://nationalacademies.org/hmd/Reports/2004/Dietary-Reference-Intakes-Water-Potassium-Sodium-Chloride-and-Sulfate.aspx) Accessed 5/17/2019.
  • Popkin, B. M., D'Anci, K. E., & Rosenberg, I. H. (2010). Water, hydration, and health. Nutrition reviews, 68(8), 439–458. doi:10.1111/j.1753-4887.2010.00304.x

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