Severe dehydration is a well-recognized medical crisis. Brought on most often by prolonged bouts of diarrhea, vomiting or intense heat-related exercise, it can cause electrolyte imbalances, kidney failure, seizures and even death.
Mild dehydration, or hypohydration, however, has symptoms that are much more subtle, and it’s the last thing most physicians would consider as an underlying cause of ill health.
But any degree of dehydration throws your body into rationing mode, which is why staying hydrated is so important. To ensure survival, water is doled out sparingly, leaving organs and tissues to deal with the consequences. Here are the side effects of dehydration:
Urinary Tract Woes
When you aren’t staying hydrated, your urine becomes concentrated, making it easier for calcium and other minerals to precipitate out and create crystals. Over time, these crystals may form into small hard masses (kidney stones) that are excruciatingly painful when passed out of the body.
Urinary tract infections (UTIs) can also be prevented by staying hydrated. Drinking lots of water increases urination and flushes bacteria out of the bladder and urethra. Upping your water intake to eight ounces per hour is actually a recommended treatment for UTIs.
Constipation responds well to increased water intake. As food moves through your digestive tract, water is absorbed by the colon. When too much water is removed, stools become dry and hard.
Most everyone knows that fiber is helpful for constipation because it hangs onto water and keeps the stool soft and bulky. But, you can eat fiber by the bucketful and you’re still going to have problems if you aren’t staying hydrated.
Water also induces gallbladder emptying, which helps prevent the formation of gallstones.
Some people swear a glass of water also relieves heartburn, and it can decrease acid levels in the stomach. Be aware, however, that water on an empty stomach increases symptoms of heartburn in some people. If you’re one of them, you’re better off drinking it with meals.
Mild dehydration increases the risk of numerous cardiovascular concerns, including stroke and venous thrombosis. However, water’s effects on hypertension (high blood pressure) are the best studied.
When your brain senses that water supplies are low, it prompts the release of vasopressin, the antidiuretic hormone. Vasopressin signals your kidneys to conserve, or reabsorb, more water and your arteries to constrict—a classic recipe for high blood pressure.
Taking drugs to lower blood pressure may make matters worse. The first-line therapy for hypertension is diuretics, so-called “water pills.” Diuretics lower blood pressure by prompting the kidneys to get rid of sodium and water. In other words, these drugs make you urinate more. Problem is, this can lead to dehydration as well as losses of water-soluble nutrients.
Chronic mild dehydration increases as we get older, thanks to changes in water-regulating hormones and declines in kidney function. In addition, our sense of thirst becomes less acute—we just don’t notice that we’re thirsty.
Short periods of water restriction have been shown to impair alertness and ability to concentrate in people of all ages. I’m not saying that staying hydrated is going to make anyone mentally sharper.
But, mild to moderate dehydration appears to exacerbate cognitive dysfunction in older people, and some experts believe it may be a risk factor for more serious dementia and Alzheimer’s disease. Residents of assisted-care facilities and individuals with cognitive impairment or poor mobility are at greatest risk.
From Asthma to Weight Loss
If what you just read isn’t enough to convince you that drinking plenty of water is essential to your health, here are some other considerations.
Increasing your water intake has also been shown to:
- Reduce exercise-induced asthma
- Improve joint and back pain by hydrating the cartilage
- Prevent dental problems by ensuring adequate saliva production
- Reduce post-exercise muscle soreness by flushing out toxins, and
- Keep the skin firm by toning up collagen.
Staying hydrated even appears to help with weight loss by suppressing appetite, burning a few calories and preventing water retention.
WATCH: Dr. Whitaker Talks About How Much Water You Need to Lose Those Extra Pounds