It’s not just summer sun that can lead to dehydration. People of all ages and activity levels can become dehydrated any season of the year, but most commonly in very hot or cold weather.
The human body is made up mostly of water, and dehydration happens when the body loses more fluid than it takes in. Mild dehydration can be reversed simply by drinking water. But when a person becomes severely dehydrated, it is a serious medical condition that requires immediate treatment.
Causes of Dehydration
Dehydration happens when the body’s functions are affected by net fluid loss, meaning you lose more fluid than you take in.
Common causes of dehydration include:
- Exercising in very hot or cold weather
- Illnesses involving vomiting or diarrhea (the most common cause in children)
- Food poisoning
- Morning sickness
- Hangovers
- Certain medications
Exercising in winter, especially in heavy layers, can lead to fluid loss from sweating. At the same time, cold weather reduces a person’s natural feelings of thirst. And exposure to the cold, dry outdoor air of winter’s freezing temperatures or to dry indoor heating – for those of us in the rainy Pacific Northwest – can all contribute to a person becoming dehydrated.
People become more susceptible to dehydration as they age because of changes in the body, reduced thirst, and not drinking enough water. In older adults, this natural susceptibility to dehydration is increased by certain medications.
At any age, doing strenuous physical activity in hot weather – especially if the level of exercise or the temperature is higher than a person is used to – can cause dehydration.
Most people are less likely to think about dehydration risk during winter, and may ignore the signs until it becomes severe.
Symptoms of Dehydration
The most obvious signs of dehydration are feeling thirsty and having a dry mouth. But dehydration can occur without feeling thirsty.
Other symptoms of dehydration include:
- headaches
- dry, itchy skin
- constipation
- dark-colored urine
- fatigue
- irritability, or
- difficulty concentrating.
Symptoms in children may include crying without shedding tears, or developing a hollow or sunken look in the eyes and cheeks, or pain in the abdomen.
In warm weather or when bundled up in cold weather, sweating can disguise dry skin. So if you suspect you may be dehydrated, try the pinch test to be sure. Skin that doesn’t “snap back” but takes time to return to normal after pinching indicates reduced elasticity, which is a sign of dehydration.
Urine color can also show a person’s hydration level – clear or pale yellow means you’re hydrated, but the darker the urine becomes, the more dehydrated you are. If dehydration is not treated, it can result in constipation or a reduced need to urinate.
When dehydration becomes serious, a person can stop sweating, which puts them at risk for heat stroke. They may become disoriented and even lose consciousness. Extreme dehydration can also contribute to kidney stones or even kidney failure.
At the first signs of dehydration, it’s important to drink fluids, especially water. If symptoms are extreme, seek medical help immediately.
How Much Do You Need to Drink To Stay Hydrated?
Thirst is a signal that your body is already lacking in fluids. Instead of waiting until you feel thirsty, it’s important to drink water throughout the day, and before exercising, especially in very hot or cold temperatures.
In most cases, drinking plain water is the best treatment for dehydration, and a good way to prevent it. Caffeinated and/or sugary beverages (which include most sports and energy drinks), as well as alcohol, can actually increase your risk of dehydration.
So how much fluid is enough to keep you hydrated?
The U.S. National Academies of Sciences, Engineering, and Medicine determined that on average, the recommended daily fluid intake is:
- Men: about 15.5 cups (124 ounces) of fluids a day (one cup = 8 oz.)
- Women: about 11.5 cups (92 ounces) of fluids a day
- Children: half of their weight in ounces (ex: 60 lbs = 30 oz. of water/day)
In older children and adults, about 20% of this amount is usually absorbed from foods such as fruits and vegetables.
In addition to hydration, food will also provide sufficient electrolytes (unless there is an underlying health concern or you tend to drink an excessive amount of water, which can dilute electrolytes in the blood).
Hydration via fluids should come from mostly water, as well as (low or no sugar) electrolyte drinks, herbal tea, broth, or milk.
The actual amount a person needs to drink to stay hydrated will vary from person to person, based on age, sex, pregnancy status, and activity level.
Working or Exercising in Heat
The CDC suggests that while working or exercising in the heat, individuals should drink about 32 ounces of fluid per hour (4 cups). Dividing that amount into 8 ounces (1 cup) every 15–20 minutes is more effective than guzzling the full amount in one go.
Drinking too much water all at once (as you might do if you become dehydrated) can cause the concentration of salt in the blood to drop too low, which can be dangerous.
Drinking more than 48 ounces (6 cups) of water in an hour can create a medical emergency requiring IV fluids to restore balance. This is one scenario when electrolyte drinks may be very useful.
A common rule of thumb when working or exercising in the heat is to replace every third bottle of water with an electrolyte drink. Meaning, drink 2 bottles of water, then 1 electrolyte drink, then water again. Salt tablets are not recommended.
Treating Dehydration
If you begin experiencing symptoms of dehydration, get out of the sun immediately and drink water. Remove layers of clothing and if you have access to ice packs, place them in the armpits or groin area.
Full recovery from dehydration can take days, but symptoms should begin to improve within a few minutes of drinking water.
If drinking water doesn’t provide relief right away, or if symptoms are severe (high fever, faintness, dizziness, nausea, rapid pulse, or an altered mental state), call 911 or go to the nearest emergency room.
In Conclusion
Dehydration affects people of all ages and activity levels any time of year. Knowing the signs of dehydration can help you treat it early to avoid serious health issues.
If you have questions or need support about how to stay hydrated and healthy, request an appointment with a WWMG Family Medicine provider today. For additional guidance on healthy eating, and appropriate activity level for your lifestyle, ask your primary care provider for a referral to WWMG’s Nutritionist/ Dietitian.