Dehydration

Water is essential to life. On average, half or more of an adult's body weight is made up of water. And it's important for us to drink enough water to keep our body fluids in balance and help our bodies maintain proper temperature. Otherwise, we run a risk of dehydration.

The Centers for Disease Control and Prevention (CDC) say dehydration is a condition in which water or fluid loss far exceeds fluid intake. The body becomes less able to maintain adequate blood pressure, deliver sufficient oxygen and nutrients to the cells and rid itself of wastes.

Symptoms of dehydration include:

• thirst
• fatigue
• weakness
• decreased urination and a dark yellow color of the urine

Left unchecked, dehydration can even be fatal.

Who's at risk?

There are times when we're more at risk of dehydration. For example, the American College of Sports Medicine (ACSM) says that as we get older, our body's ability to conserve water is reduced. In other words, our bodies may start to excrete more water (through urination and perspiration) than we take in. (Read about "Sweating") In addition, ACSM says other changes associated with aging may make us more vulnerable to dehydration. These include:

• hormonal changes associated with menopause (Read about "Menopause")
• some types of chronic medical conditions, for example, hypertension (Read about "Hypertension: High Blood Pressure")
• certain medications, such as those used for urinary incontinence problems (Read about "Incontinence")
• changes to the urinary system as we age (Read about "The Urinary System")

Unfortunately, by the time someone starts to feel thirsty, his or her body has already lost fluids. So it's important for older people and their families to be aware of this risk - especially if they're using medications on a regular basis - and to discuss their potential risks with their doctors.

Fluids, heat & exercise

There are other times when the risk of dehydration increases for everyone regardless of age, for example:

• during hot weather (Read about "Heat Stroke")
• during humid weather
• when we exercise.

The National Center for Environmental Health says that during hot weather, we need to drink more liquid than our thirst indicates, especially if we're over 65 years of age. (If your doctor has prescribed a fluid-restricted diet or diuretics for you, ask your doctor how much you should drink) The reason seniors are more at risk of dehydration is because as we get older, we have a decreased ability to respond to external temperature changes and a decreased thirst mechanism (ability to feel thirsty).

When you're exercising, the American Council on Exercise recommends drinking 6-8 ounces of fluid for every 15-20 minutes of exercise. Water can be one of the best fluids to drink. But you can also get too much of a good thing. The military and marathon groups warn their members to watch out for what is called hyponatremia or water intoxication. It happens when only fluids are replaced during long periods of exercise and sodium levels in the blood drop. The American Dietetic Association says you can get fluids from beverages besides water; however, alcoholic and caffeine-containing beverages tend to have a diuretic effect, i.e. they cause the body to lose water, so these types of beverages are not as much of a help against dehydration.

Diarrhea

Another time of danger from dehydration comes when a person, especially the elderly and very young children, have a bout of diarrhea. (Read about "Diarrhea") It is important to ingest fluids and minerals (Read about "Vitamins & Minerals") that are lost. CDC also warns about traveler's diarrhea, caused by contaminated food or water. (Read about "Travel and Health")

Related Information:

    Digestive System