It’s not unusual to crave a cold glass of water on a hot summer day or after you’ve eaten something particularly spicy. But there are multiple reasons why you may suddenly find yourself thirsty and some are more serious than others.
One of the most common reasons you’re probably thirsty is dehydration. Overheating is one of the biggest causes of dehydration. Whether you’ve been rigorously exercising or just resting in the sun at the beach, your body needs water to keep 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.
According to the American College of Sports Medicine, to avoid dehydration, active people should drink at least 16 to 20 ounces of fluid one to two hours before an outdoor activity. After that, you should consume 6 to 12 ounces of fluid every 10 to 15 minutes that you are 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 (2 to 3 cups).
One way to make sure you are properly hydrated is to check your urine. Matthew Goldman, MD, says, “The goal is to keep the urine clear. If it starts to become yellow, then you’re getting dehydrated.”
Certain foods are also great at helping you stay hydrated thanks to being heavy on water content. And many have added benefits of including other essential nutrients your body needs. Vegetables such as cucumbers and celery aren’t just high in water content, they’re also low in calories, making for a perfect snack.
If you’re looking for fruits, both watermelon and strawberries are excellent choices with 91% water content and make for great, sweet treats, especially in hot weather.
Drinking water is one of the best ways to stay hydrated but some sports drinks can also assist in replacing not just fluids but electrolytes such as sodium and potassium. But try to avoid alcohol and caffeinated beverages, such as coffee and sodas, as these fluids tend to pull water from the body and promote dehydration.
Increased urination and excessive thirst are two telltale signs of the onset of type 2 diabetes. It can also be an indicator of hyperglycemia, a condition where there is too much sugar in the blood, most often experienced by those with diabetes.
According to the CDC, “Eating too much food, being less active than usual, or taking too little diabetes medicine are some common reasons for high blood glucose (aka hyperglycemia). Your blood glucose can also go up when you’re sick or under stress.”
“Normally, the amount of sugar leaving the body through the urine is not detectable,” explains Dr. Goldman. “However, if someone’s blood sugar level is elevated enough, sugar begins to leave the bloodstream through the kidneys and enters the urine.”
The glucose (“sugar”) molecules are small enough to leak out through the filtration system of the kidneys. As the excessive glucose molecules enter the urine, the glucose draws water with it like a sponge. As a result, the amount of urine formed and frequency of urination increases. As we lose those excess fluids, we eventually become dehydrated.
This is why patients who have elevated blood sugar levels for too long often become “dried up” and may end up in the emergency department or intensive care unit. Once they arrive, they often require a lot of fluids (through IV) as well as vitamins and medications to get their sugar levels under control in a safe manner.
Dehydration could also be a sign of a condition known as diabetes insipidus. According to Dr. Goldman, “Antidiuretic hormone (ADH) is a hormone that allows the body to reabsorb water from urine that is forming in the kidneys. This reabsorption tends to occur most when we are becoming dehydrated, such as while we sweat.”
If the body isn’t producing enough ADH or the kidneys aren’t responding appropriately to ADH, then the body doesn’t retain as much water as it may need; this may result in more frequent urination and possibly dehydration.
“Patients should speak to their provider about sugar levels and what is considered a normal blood sugar level for themselves as well as what to do if these levels become abnormal,” suggests Dr. Goldman.
“In general, patients should avoid drinking fluids to have excessive amounts of sugar in them because this may eventually lead to uncontrolled blood sugar levels and cause the amount of urination to worsen,” Dr. Goldman says.
“One reason patients should take in some extra sugar is if their blood sugar level is too low. Patients should speak to their provider further about what is considered a normal as well as low sugar for themselves,” he adds.
Certain medications your doctor prescribes may cause certain side-effects, including thirst.
“Lithium is a medication that is widely known to possibly result in excessive urine output and therefore increased thirst,” according to Dr. Goldman. “Over time, it may eventually block the activity of antidiuretic hormone (ADH) in the kidneys, which leads to excess urination and thirst,” he says. A number of other medications — antipsychotics, antidepressants, anticonvulsants, anticholinergics and alpha agonists — can cause dry mouth and, therefore, trigger thirst.
Dr. Goldman also notes that SGLT2 inhibitors (a kind of diabetes medication) as well as steroids can also cause thirst since SGLT2 inhibitors increase the release of glucose from the blood into the urine to lower blood sugar levels and steroids often raise sugar levels as a side effect.
This is why, when someone is placed on steroids (whether short or long term), they may be encouraged by their provider to monitor their blood sugar or accommodate the higher sugar levels by taking more medications for diabetes.
Dr. Goldman says you should talk to your provider about these side-effects and see if there are alternative medications available.
Until you and your provider can discuss alternatives, continue taking your medication as directed.