Dehydration is defined as an abnormal loss of water from the body. The human body is made of 60% water. Even a 1.5% loss of water can trigger dehydration, leading to changes in mood, decreased energy and decreased mental clarity. This happens when your body loses and/or uses more water than you take in from drinking and eating. Dehydration can happen in any situation, at any time of year, however hot summer and early fall days increase the risk. Other factors that increase risk for dehydration are strenuous exercise, extreme temperatures (hot or cold), illness (vomiting, diarrhea, inability to drink enough) and air travel. Anyone can become dehydrated; however young children and older adults are at higher risk.
Signs of dehydration include:
- Increased thirst
- Urine is low volume and darker than usual, the color of apple juice instead of lemonade
- Dry mouth
- Flushed skin
- Faster breathing and pulse rate
Dehydration is preventable by drinking and eating adequate amounts of fluid. But how much is that? According to the Institute of Medicine, an adequate intake (AI) for men is 13 cups (3 liters) of total beverages daily and for women, 9 cups (2.2 liters) of total beverages daily. People who are active have higher fluid requirements. The American College of Sports Medicine recommends drinking at least 2-2 ½ cups (16-20 ounces) of fluid one to two hours before an outdoor activity and 3/4 to 1 ½ cups (6 to 12 ounces) of fluid every 10 to 15 minutes you are outside. Afterward, drink 2 to 3 cups (16-24 ounces) of fluids. Weigh yourself before and after exercise, for every pound lost, drink 20-24 extra ounces of fluids.
Water is the best thing to drink to stay hydrated as it offers numerous benefits, including:
- Maintains body temperature
- Lubricates and cushions joints
- Protects the spine and other tissues
- Helps eliminate waste through urine, sweat and bowel movements
- Aids in digestion and absorption
- Keeps skin looking healthy
- Calorie free
- Often, it is free
Good fluids options to stay hydrated include:
- Water (add lemon or lime wedges, cucumber or ice cubes made of no sugar added juice to make it a little more exciting)
- Flavored, carbonated water with no calories
- Fat free or skim milk
- Coconut water
- Coffee or tea
*A note about coffee and tea: caffeine is a diuretic, however studies have shown coffee intake in moderation (1 to 4 cups per day) has not been shown to cause dehydration and can provide hydration similar to water.
Foods can contribute 20% of your total daily fluid requirement. Foods high in water content include:
- Cottage cheese
- Water packed tuna fish
Less ideal fluid options include soda, juice and sports or energy drinks as they are often high in sugar and calories. Alcohol is a diuretic and can contribute to dehydration.
Is it possible to be over-hydrated? Although rare, it is possible and potentially dangerous. Over hydration happens when fluid intake is more than the kidneys can remove in the urine, about ½ liter per hour. In general, a person would have to consistently drink at least 6 gallons of water daily to cause over hydration. This can lead to hyponatremia, a dangerous imbalance of sodium in the body. Symptoms of over hydration can be similar to dehydration:
- Nausea and vomiting
- Muscle spasms, cramps or weakness
As opposed to dark colored urine when dehydrated, urine will be colorless if over-hydrated. People at highest risk for over hydration are endurance athletes who drink an excessive amount of fluid in a short period of time. Drinking fluids with sodium and potassium during and after strenuous exercise can help maintain electrolyte balance in the body.
Tips for increasing water intake and staying hydrated:
- Find a water bottle you really like and will use, then take it with you everywhere
- Drink a glass of water before and after each meal
- Make water more enjoyable by adding lemon, lime, cucumber, or ice cubes made of no sugar added juice
- Drink flavored, carbonated water with no calories
- Don’t wait until you’re thirsty to drink water
- Monitor urine color; lemonade is good, apple juice is too dark
- Increase water/fluid intake when exercising, especially outside in the heat
- Eat fruits and vegetables high in water content
Jill Irvine is a registered dietitian, certified dietitian, and certified nutrition support clinician who works in the Neonatal Intensive Care Unit at The University of Washington Medical Center. She enjoys run commuting to work and tries to drink a gallon of water every day.