Not drinking enough fluids?

Originally Published: January 27, 1995 - Last Updated / Reviewed On: April 16, 2014
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Dear Alice,

I hardly drink any fluid during the day; maybe a glass of water with my evening meal. I've been like this my whole life — I just don't get thirsty. Someone told me that this is dangerous. What do you think? I don't handle warm temperatures very well. Could it be related?

—The Lizard

Dear The Lizard,

Water, water everywhere, but not a drop to drink. While our individual needs for water vary, water is essential to various bodily functions, such as maintaining body temperature and transporting vitamins and minerals to needed areas of the body. Certain people, i.e., the elderly and those who have certain brain injuries, may not feel thirsty when their bodies actually need water. Discussing this issue with a health care provider may prove to be a watershed event in understanding why you don't get thirsty.

The who, what, when, why, and how of thirst begins with the hypothalamus in the brain. Special sensors in the hypothalamus monitor the body's concentration of electrolytes such as sodium, as well as blood pressure and blood volume. When we don't have enough water in our bodies, the hypothalamus "tells" us to drink something. The hypothalamus also increases the amount of vasopressin, a hormone that tells the body to hold the water gates. When vasopressin gets to our kidneys, the water there becomes reabsorbed from the urine until we start drinking something. As mentioned before, the thirst mechanism may be affected by age and/or other factors.

People stay hydrated in a number of ways. Drinking water, low fat milk, herbal teas, or seltzer water flavored with juice are all options. Keep in mind that the fluids that are present in foods that we eat also contribute to our daily fluid quota. If fact, we typically get 20 percent of our fluids from foods and 80 percent from liquids. Tips to stay hydrated include the following:

  • Drink eight glasses of water per day (1.9 liters) OR drink enough fluid so that you don't feel thirsty (FYI, we pee out about 6.3 cups, or 1.5 liters of urine per day, so replenishing this amount and then a little extra may be a good idea).
  • Drink a cup of water with every meal you eat, as well as between each meal
  • Drink plenty of fluids before and after you exercise
  • Skip the alcohol at parties and drink sparkling water instead (you can flavor it with your favorite juice)
  • Consume foods that have a high water content, i.e., watermelon, tomatoes
  • If you don't like the taste of water, consider flavoring it with fruit juices, or drinking low-fat milk or herbal teas (options without caffeine)
    List adapted from Water: How much should you drink every day? from the Mayo Clinic.

You mentioned that you "don't handle warm temperatures very well." Because water helps regulate body temperature, not drinking enough may lead to overheating. Since more fluids are lost in hotter temperatures due to sweating, dehydration can become dangerous. Symptoms of dehydration include dry mouth, dark yellow urine, and lethargy. Keeping hydrated when it's hot, or during exercise, helps to prevent dehydration. For more information, check out other related Q&As in the Go Ask Alice! Nutrition and Physical Activity archives

If you're a student at Columbia, you can make an appointment to discuss this issue with a health care provider at Medical Services (Morningside) or the Student Health Service (CUMC).

If this response is making you thirsty, the first drink is on the house.

Alice