Not drinking enough fluids?

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,

You’ve come to the right place to quench your thirst for knowledge about hydration. While individual needs for water vary, water is essential to various bodily functions, such as maintaining body temperature, blood flow, kidney function, 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. In addition to learning more about how hydration works and why the body needs water, it may be helpful to discuss your concerns with a health care provider to see if there’s a link between your hydration habits and your ability to handle warmer temperatures.

A part of the brain called the hypothalamus acts as the body’s thirst control headquarters. Special sensors in the hypothalamus monitor the body's concentration of electrolytes, as well as blood pressure and blood volume. When there isn’t enough water in the body, one type of sensor indicates a need to drink something. The other type of sensor signals to reduce the amount of urine excreted by increasing the amount of the hormone vasopressin in the bloodstream. When vasopressin gets to the kidneys, the water there is reabsorbed from the urine until more fluids are consumed. How thirsty a person feels is impacted by a number of factors such as age and weather conditions, among others.

Staying hydrated will help ensure that the body stays healthy. There are plenty of easy and tasty ways to stay hydrated. 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 also contribute to your daily fluid quota. In fact, approximately 20 percent of fluids are consumed from foods and 80 percent from liquids. If you’re hoping to up your hydration game, you may try some of the following strategies:

  • Aim for eight glasses of water per day (1.9 liters) or drink enough fluid that you don't feel thirsty; most people 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.
  • Try scheduling times to drink water such as including a cup with every meal you eat, as well as between each meal.
  • If you’re going to be active, have at least one cup before, during, and after you exercise.
  • 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.
  • Stay adequately hydrated by increasing your fluid intake in certain situations, such as when you’re sick, in a hot or humid climate, drinking alcohol, or physically active.
  • Try carrying a water bottle with you wherever you go.
  • The feelings of being thirsty or hungry can be similar, so it may be a good idea to try drinking water first before grabbing a bite.

List adapted from Mayo Clinic and American Academy of Family Physicians.

Other drinks, such as coffee and soda, can also contribute to your daily water intake but it’s recommended that you consume these in moderation, especially for beverages with caffeine. Caffeine acts a diuretic, so it may be wise to keep an eye on how much is in your drinks (no more than two to four eight-ounce (oz.) cups of coffee or less a day is recommended) if you’re trying to stay hydrated.

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 the rate of fluid loss is higher in hotter temperatures due to sweating, dehydration may become a concern. Symptoms of dehydration include dry mouth, dry skin, dark yellow urine, constipation, and lethargy. Dehydration may seem benign, but it can lead to a number of health complications, ranging from heat injuries (heat stroke, heat cramps) to hypovolemic shock, which is a drop in blood volume, causing reduced blood pressure and blood oxygen. People with chronic illnesses may also be more susceptible to being more at risk of dehydration. You may find it useful to speak with a medical professional to explore your inability to handle heat well. For more information on staying hydrated, check out other related Q&As in the Go Ask Alice! Nutrition & Physical Activity archives. 

Hope these tips made a splash,

Last updated Jul 28, 2017
Originally published Jan 27, 1995

Submit a new comment


This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.

The answer you entered for the CAPTCHA was not correct.