What is dehydration?
Warm weather brings with it thoughts of cool ocean breezes, napping in a hammock and sipping a tall glass of lemonade. Now hold on to the mental image of that lemonade because summer is also a time to be wary of dehydration: the lack of sufficient water in your body, specifically in your cells and blood vessels. Even losing a little bit, as little as 1.5% of your body’s water, can cause symptoms. Those symptoms can be as simple as a slight headache, or the dehydration could contribute to a life-threatening illness like heatstroke (hyperthermia).
Your body’s natural response to inadequate hydration is thirst. You should respond to thirst right away by drinking fluids – preferably water. Drink enough water to prevent yourself from feeling thirsty! Water has zero calories!
What does water do for your body?
Between about 55% to about 78% of your body is made of water. Newborn babies are about 78% water, a year-old baby is 65%, adult men are about 60% and adult women are about 55%. Your brain is made up of 73% water, and so is your heart. Your bones are 31% water, muscles and kidneys are 79% and your skin is 64%. A whopping 83% of water makes up your lungs.
- Aid digestion and get rid of waste.
- Work your joints. Water lubricates them.
- Make saliva (which you need to eat).
- Balance your body’s chemicals. Your brain needs it to create hormones and neurotransmitters.
- Deliver oxygen all over your body.
- Cushion your bones.
- Regulate your body temperature.
Act as a shock absorber for your brain, your spinal cord and, if you’re pregnant, your fetus.
Water is important to your body, especially in warm weather. It keeps your body from overheating. When you exercise, your muscles generate heat. To keep from burning up, your body needs to get rid of that heat. The main way the body discards heat in warm weather is through sweat. As sweat evaporates, it cools the tissues beneath. Lots of sweating reduces the body's water level, and this loss of fluid affects normal bodily functions. Drink water!
Are hypovolemia and dehydration the same?
No, these terms do not mean the same thing. Hypovolemia defines many conditions where extracellular fluid volume is reduced. Dehydration can be one of several causes of hypovolemia, but it is not the same thing as it.
Are dehydration and hypernatremia the same?
No. Again, dehydration can be a cause of hypernatremia, but it is not the same thing.
What causes dehydration?
Dehydration happens when you don’t drink enough water, or when you lose water quickly through, for example, sweating, vomiting and/or diarrhea. Certain medications such as diuretics (water pills) can result in increased urination and dehydration.
Who’s at risk of becoming dehydrated?
Anyone can become dehydrated if they don’t take care of themselves and drink water. However, infants and children, especially when they’re sick, are at a higher risk because they may be unable to communicate that they’re thirsty. Monitor the amount of fluids your kids take in.
Older adults are also at a higher risk. Their body’s fluid reserves shrink and their body’s ability to tell them they’re thirsty doesn’t work as effectively. This means they don’t carry as much water in their bodies and they can’t tell as easily when they’re thirsty. If you’re a caretaker of an elderly individual, especially one who may have memory problems, offer them drinks frequently. Even if they’re enduring an uncomfortable infection like a UTI (urinary tract infection), they still need to consume liquids.
What are the signs of dehydration? What does dehydration feel like?
If you suspect that you or someone else is severely dehydrated, seek immediate medical attention.
Signs of dehydration include:
- Headache, delirium, confusion.
- Tiredness (fatigue).
- Dizziness, weakness, light-headedness.
- Dry mouth and/or a dry cough.
- High heart rate but low blood pressure.
- Loss of appetite but maybe craving sugar.
- Flushed (red) skin. Swollen feet. Muscle cramps.
- Heat intolerance, or chills.
- Dark-colored pee (urine). Your pee should be a pale clear color.
The best way to beat dehydration is to drink before you get thirsty. If you wait until after you're thirsty, you're already dehydrated.
In what other ways does dehydration affect me?
Dehydration does more than you might expect. If affects you not only physically (note the signs stated above), but mentally and emotionally as well. If you’re dehydrated, you may feel:
- Like you can’t remember.
Note that these symptoms may be worse in someone who has dementia.
How does dehydration affect the brain?
Severe hydration shrinks the blood vessels in the brain. When there aren’t high enough fluid levels in your brain, that affects your memory and coordination.
How does dehydration affect the heart? Can dehydration cause high blood pressure?
Your heart has to work harder when there’s less water in your blood.
How does dehydration affect the kidneys?
The average person urinates (pees) about six or seven times a day. If you’re dehydrated, you may urinate less. This is because less water in your blood causes your kidneys to hold on to the urine.
Does dehydration cause cramping?
Loss of electrolytes, like sodium and potassium, can cause cramping. They’re expelled through perspiration (sweating). Drink water, but also a sports drink to replenish your electrolytes if your fluid losses are extensive from sweating, vomiting or diarrhea.
Can medications cause dehydration?
Diuretic medications, which are prescribed to treat heart failure and high blood pressure, can increase your risk of dehydration.
Can dehydration cause shortness of breath?
Shortness of breath is not a symptom of dehydration. However, it may go alongside dehydration. For example, you might be playing a sport outside in the hot sun and get dehydrated from lack of water and also feel short of breath from all the activity.
Care and Treatment
How is dehydration diagnosed?
Don’t forget that if you feel thirsty, you’re already dehydrated. That’s the easiest way to tell that you need more fluids.
Laboratory tests can also diagnose dehydration. Tests include:
- Low urine sodium concentration.
- Elevated plasma serum osmolality. This measures how concentrated some particles are in your blood plasma.
- Elevated creatinine. This tests kidney function.
- Elevated blood urea nitrogen. This also relates to kidney function.
What are the levels of dehydration?
Dehydration may be categorized as:
- Mild. You just have to take in more fluids orally (by mouth). Drink water, but replace fluids with a drink that contains electrolytes if you experience significant sweating or fluid losses from vomiting and diarrhea. You should feel better after five or 10 minutes.
- Moderate. Moderate dehydration requires an IV (intravenous hydration). You’ll get this in an urgent care, emergency room, or hospital.
- Severe. See a healthcare provider if your symptoms of dehydration are severe. Call 911 or go to an emergency room.
If you’re seeing a healthcare provider, they’ll figure out what level you’re at in order to assign you treatment.
How is dehydration treated?
Drink water. You could also try increasing your hydration with oral rehydration sachets – powders you mix in with your water.
How long does it take for the symptoms to stop after water is ingested?
You may see the symptoms of dehydration improve in as little as five to 10 minutes.
How do I prevent dehydration?
Exactly how much water do you need? That depends on your weight, age, level of activity, age, the climate of your environment and other factors. Those with diabetes, heart disease, cystic fibrosis and other conditions may need to be cautious. The amount of water you need can also depend on the climate and what clothes you’re wearing. Although the standard advice is eight glasses of water per day (about 2.2 liters or 2.3 quarts per day for an adult female and about 3 liters or 3.2 quarts per day for an adult male), talk to your healthcare provider to confirm the right amount for you.
Keep track of how much fluid you drink. Drink water throughout the day, including at meals. Avoid soda, alcohol and caffeinated drinks. One way to make sure you are properly hydrated is to check your urine. If it's clear, pale or straw-colored, it's OK. If it's darker than that, keep drinking!
To avoid dehydration, active people – people playing a sport or exercising – should drink at least 16 to 20 ounces of fluids one to two hours before an outdoor activity. After that, you should consume six to 12 ounces of fluid every 10 to 15 minutes when you’re outside. When you are finished with the activity, you should drink more. How much more? To replace what you have lost: at least another 16 to 24 ounces.
Which beverages hydrate the body, and which dehydrate?
Some beverages are better than others at preventing dehydration. Water is all you need if you’re planning to be active in a low or moderate intensity activity, such as walking for only an hour or less. If you plan to exercise longer than that, or if you anticipate being out in the sun for more than a few hours, you may want to hydrate with some kind of sports drink. These replace not only fluid, but also electrolytes like sodium and potassium, which are lost through sweating. Too much or too little sodium and potassium in the body can cause trouble. Muscle cramping may be due to a deficiency of electrolytes.
Beverages containing alcohol or caffeine aren't recommended for optimal hydration. These fluids tend to pull water from the body and promote dehydration. Fruit juice and fruit drinks may have too many carbohydrates, too little sodium and they may upset your stomach.
Adequate hydration will keep your summer activities safer and much more enjoyable. Keep an extra pitcher of water in the refrigerator and add fresh lemons, limes, cucumber or mint for a dash of flavor.
How do I get myself and my loved ones to drink more water?
- Carry a water bottle with you. Keep it filled!
- Choose water instead of sugary drinks, including at meals.
- Add flavor. A wedge of lime or lemon might make it tastier, and more fun! You can also try some flavored drink mixes, but watch out for the sugar!
- Eat foods that are high in water content. Many soups, fruits and vegetables meet this description.
- If you don’t like drinking a lot of water at once, try smaller doses spread out throughout the day.
When to Call the Doctor
When should I contact a healthcare provider about dehydration? At what point is dehydration dangerous?
The amount of water needed on a daily basis depends on many factors, so it’s best to check in with your healthcare provider to determine exactly how much will keep you healthy.
Always drink water immediately if you feel thirsty. Remember – if you feel thirsty, you’re already dehydrated. You may see the symptoms of dehydration improve in as little as five to 10 minutes.
If you think your symptoms of dehydration are severe, don’t hesitate to seek help! Dehydration can contribute to kidney stones, kidney failure and heatstroke, all life-threatening illnesses. Call 911 or go to the emergency room right away if you have symptoms of severe dehydration, or (see below) heatstroke:
- A temperature of 103 degrees Fahrenheit or higher.
- Muscle twitching.
- Red, hot, dry skin.
- Rapid pulse.
- Lack of sweating.
- Confusion, altered mental state, slurred speech.
- Fainting, loss of consciousness.
What is dehydration causes and symptoms? ›
Check if you're dehydrated
feeling thirsty. dark yellow, strong-smelling pee. peeing less often than usual. feeling dizzy or lightheaded.
What causes dehydration? Dehydration happens when you don't drink enough water, or when you lose water quickly through, for example, sweating, vomiting and/or diarrhea. Certain medications such as diuretics (water pills) can result in increased urination and dehydration.What are 10 signs and symptoms of dehydration? ›
- Extreme thirst.
- Urinating less than usual.
- Dark-colored urine.
- Sluggishness and fatigue.
- Bad breath.
- Dry mouth.
- Sugar cravings.
Dehydration is usually caused by not drinking enough fluid to replace what we lose. The climate, the amount of physical exercise you are doing (particularly in hot weather) and your diet can contribute to dehydration.What happens to your body when you are dehydrated? ›
Effects of Dehydration
As you lose fluid, your blood becomes more concentrated, making your cardiovascular system work harder to efficiently pump blood. A high blood concentration also makes your kidneys retain more water, which is why you urinate less.
- WATER. If you have to ask how to rehydrate, then the answer is a definite no-brainer: drink water. ...
- COFFEE & TEA. ...
- SKIM & LOW FAT MILK. ...
- FRUITS AND VEGETABLES. ...
- ORAL HYDRATION SOLUTIONS.
- Heat exposure. Spending time in hot or humid conditions can lead to increased fluid loss through sweating.
- Illness. ...
- Mobility problems. ...
- Underlying health conditions. ...
For most people, drinking water is the best way to stay hydrated and rehydrate. Other options include coffee, tea, milk, fruits, vegetables, and oral hydration solutions. Don't hesitate to speak with your healthcare provider if you're concerned about your or someone else's hydration status.What are the symptoms of dehydration in the elderly? ›
- Confusion or disorientation.
- Dry mouth.
- Loose skin or skin that doesn't return to normal after pinching.
- Urinating less than usual.
Cantaloupe, grapefruit, strawberries, watermelon, broccoli, cabbage, cauliflower, celery, cucumbers, eggplant, lettuce, sweet peppers, radishes, spinach, zucchini, and tomatoes are all at least 90% water. Soups, popsicles, water ice, and gelatins are also high in water.
Is Gatorade good for dehydration? ›
Pedialyte and Gatorade are both designed to prevent or treat dehydration. In fact, thanks to their electrolyte content, they're more effective than water at rehydrating.What blood test shows if you are dehydrated? ›
An electrolyte panel is a blood test that measures the levels of seven electrolytes in your blood. Certain conditions, including dehydration, cardiovascular disease and kidney disease, can cause electrolyte levels to become too high or low. This is an electrolyte imbalance.Can you be dehydrated even if you drink a lot of water? ›
Or you may not even notice that you're low on fluid. This happens as your body becomes less sensitive to water intake and tries to make do with less water, regardless of how much you're drinking. Other signs of chronic dehydration include: dry or flaky skin.Can you be dehydrated and still pee clear? ›
The relationship between urine colour and hydration status
The issue is that, whilst urine colour can definitely be somewhat indicative of hydration status, there's definitely not a simple and linear relationship between actual hydration status and the colour of your pee.
You've probably heard the advice to drink eight glasses of water a day. That's easy to remember, and it's a reasonable goal. Most healthy people can stay hydrated by drinking water and other fluids whenever they feel thirsty. For some people, fewer than eight glasses a day might be enough.How long does it take to rehydrate your body? ›
In general, however, it usually takes about two hours for your body to rehydrate fully after drinking a significant amount of water. As for how you should rehydrate, water is the best choice. Sports drinks, such as Gatorade, can be helpful for athletes who need to replenish electrolytes.How long does it take for your body to recover from dehydration? ›
How long it takes to recover from dehydration depends on how dehydrated you are. Research shows that you can relieve mild dehydration in about 45 minutes. However, for moderate to severe dehydration, you'll take longer to recover, but this depends on the type and amount of fluids and electrolytes you take.Should you eat if you are dehydrated? ›
Whether you're trying to get some extra hydration or you don't like drinking your water, it's beneficial to incorporate hydrating foods into your diet, according to Harvard Medical School.What happens to your kidneys when you are dehydrated? ›
Some studies have shown that frequent dehydration, even if it's mild, may lead to permanent kidney damage. Dehydration can cause a build-up of wastes and acids in the body, and it can clog the kidneys with muscle proteins (myoglobin). All these things can hurt the kidneys.What problems can dehydration cause? ›
Symptoms can include thirst, dry mouth, and less urine. Mild dehydration can cause problems with blood pressure, heart rate, and body temperature. Severe dehydration can also cause weakness or confusion. In extreme cases, it can lead to kidney damage, brain damage and even death.
How can you tell if you are dehydrated? ›
Signs and symptoms of dehydration include dark-colored urine, decreased urination, headaches, fatigue, dry skin, decreased skin turgor, and poor concentration. Make sure you're getting enough fluids every day by drinking plenty of water or other fluids.How long does a person stay dehydrated? ›
As a general rule of thumb, a person can survive without water for about 3 days. However, some factors, such as how much water an individual body needs, and how it uses water, can affect this. Factors that may change how much water a person needs include: age.How does dehydration affect blood pressure? ›
When your body is dehydrated, it releases higher amounts of a chemical called vasopressin. Vasopressin helps your kidneys retain water, which can prevent you from losing more water through urination. At the same time, it causes your blood vessels to constrict, which then causes your blood pressure to increase.Can you drink a lot of water and still be dehydrated? ›
So, what if you drink loads of water each day but are still feeling thirsty and dehydrated? It can be a sign that something else is going on. Factors like your medication, how much you sweat and if you're sick can affect your levels of hydration.How do I fix my dehydration? ›
With beginning symptoms of dehydration, you can rehydrate by consuming fluids that contain electrolytes, such as sports drinks or oral rehydration solutions. There are also foods available that have a high water content, such as fruits and vegetables. These will also help with rehydration.