How Dehydration Affects Your Brain, Energy Levels, and Body

Most people know that dehydration is bad for them, but you may be surprised at how it can affect you.

Right now, we are still encountering the sweltering heat of summer —high temperatures are breaking records here in DC and around the world — and the Northern Hemisphere may experience its hottest year ever recorded.

There is typically a spike in dehydration in the mid- and late-summer months, when the heat index is the highest.

Aside from the general lightheaded feeling and dry mouth that individuals commonly recognize as dehydration, there are many hidden dangers that affect your physical and mental health. Our brains are highly influenced by hydration status and even mild dehydration (1-3% of body weight) can result in impaired brain function. Dehydration has been shown to negatively impact concentration, and functions such as problem-solving, motor coordination, and attention suffer the most.

Although it’s still unknown exactly when cognitive errors occur, studies show that the most severe impairments start to transpire at a 2 percent drop in body mass, a water weight loss that can happen quickly.

Surprising Benefits of Staying Hydrated

I usually tell my patients to go with the formula of 1/2 your body weight in ounces, so if you weigh 200 lbs., then you want to try to drink 100 ounces per day.

There are many benefits of staying hydrated — some you may not know about!

  • Prevent headaches: Dehydration can trigger headaches and migraines, and increasing your water intake can help.
  • Think more clearly: You may feel foggy and have trouble concentrating without enough water. Drinking up to be more productive at work!
  • Relieve constipation: Increased fluid intake can help alleviate symptoms of constipation. Low water consumption has been shown as a risk factor for constipation in young and elderly individuals.
  • Lose weight: Drinking water can increase satiety and boost your metabolic rate. Sometimes what we mistake for hunger is actually thirst.

Signs of dehydration include feelings of thirst, dizziness, heat cramps, nausea, mood changes, fatigue, and frequent headaches. In extreme cases, when left untreated, you may end up having to go to the emergency room for treatment.

How easily a person becomes dehydrated is dependent on their body mass. Younger children and infants need to monitor their hydration more than an adult would because they have a lower total body weight and a higher concentration of water. An infant’s total body water is 70 percent whereas it’s about 65 percent in older children and 60 in adults; infants and children can also turn over electrolytes and water faster than other age groups, meaning they lose water more quickly than adults.

Tips on Staying Hydrated Safely

  • Hydrate throughout the day: Drinking too much water can dilute the body, leading to a low sodium and salt intake in the blood and, in extreme cases, cause seizures. Stay hydrated by taking in fluids throughout the day, not all at once. Keep a water bottle with you!
  • Eat for the weather: Especially in hot weather and the summer months, try to consume fruits and vegetables and other foods that have high water content.
  • Exercise around the sun and heat: It’s great to stay active, but it’s best to exercise when the sun isn’t at its peak. Exercise indoors if it’s especially hot and humid outside, or go out for your walk, run or bike ride before the sun rises or after the sun sets. (Be sure to wear reflective, light weight clothing.)

Following these tips on hydration and ensuring that you always carry around extra liquids when out in the sun is a great way to ensure you don’t experience dehydration.

Stay cool! (And hydrated!)