Up to 75% of Americans do not drink enough water. Drinking water is important because even mild dehydration can affect every part of your body, from your gut to your brain. A survey of 3,003 U.S. adults found that three-quarters of the respondents had a net fluid loss, resulting in chronic dehydration. Although the survey found that many Americans do drink about eight servings of hydrating beverages daily, this is offset by drinking caffeinated beverages and alcohol and eating a high sodium diet.

According to Axios, the U.S. National Academies of Sciences, Engineering, and Medicine recommends that men drink about a gallon of water daily and the average woman should consume three-quarters of a gallon. A gallon is 128 ounces or 16 eight-ounce glasses of water. While you do get about 20% of your daily water intake from food, the rest you need to get from drinking.

Dehydration is a common cause of hospital admission, says Axios. Studies have also linked dehydration with declines in focus and short-term memory. Even mild dehydration can put stress on cognitive functioning. While anyone can become dehydrated, the condition is especially dangerous in young children and older adults, says the Mayo Clinic.

The most common cause of dehydration in children is severe diarrhea and vomiting. Older adults naturally have a lower volume of water in their bodies and may have conditions or take medications that increase the risk of dehydration.

Dehydration can lead to serious health problems including heat injury, ranging in severity from mild heat cramps to heat exhaustion or potentially life-threating heatstroke. Repeated bouts of dehydration can cause urinary tract infections, kidney stones and even kidney failure. Dehydration can lead to seizures or low blood volume shock (hypovolemic shock) which can also be deadly.

These are some of the reasons we should drink more water, but another is the fact that studies have associated drinking more water with weight loss, says Axios. Some hydration tips include drinking water throughout the day and especially before and after meals to aid digestion.

While plain water is the best choice, epidemiologist Dr. Walter Willett at Harvard’s School of Public Health says that low-sugar teas, juices, and seltzer waters also work well. According to the national Beverage Guidance Panel that included Willett, water provides everything the body needs to restore fluids lost through metabolism, breathing, sweating, and removal of waste.

To ensure you are drinking enough to reach your hydration goals, pre-fill reusable bottles of water or large pitchers and keep them in the refrigerator ready to go. You can even keep some water in the freezer so that you can take it with you when traveling so that you can enjoy cold water during the day