Dehydration: When the Body runs low of fluids

CEBU, Philippines – Among the common health threats during summer is dehydration.The condition occurs when the body uses or loses more fluid than one takes in, leaving the body with not enough water and other fluids to carry out its normal functions. If the lost fluids are not replaced in time, the person becomes dehydrated.

Common causes of dehydration include vigorous exercise, especially in hot weather, intense diarrhea, vomiting, fever or excessive sweating. Not drinking enough water during exercise or in hot weather even if not exercising may also cause dehydration. Anyone may become dehydrated, but young children, older adults and people with chronic illnesses are most at risk.

Mild to moderate dehydration can usually be reversed by drinking more fluids, but severe dehydration needs immediate medical treatment. The safest approach is preventing dehydration in the first place. One must keep an eye on how much fluid he or she loses during hot weather, exercise or illness, and drink enough liquids to replace the fluid lost.

Mild to moderate dehydration is likely to cause: dry, sticky mouth; sleepiness or tiredness (children are likely to be less active than usual); thirst; decreased urine output; no wet diapers for three hours for infants; few or no tears when crying; dry skin; headache; constipation; dizziness or lightheadedness.

Severe dehydration, a medical emergency, can cause: extreme thirst; extreme fussiness or sleepiness in infants and children; irritability and confusion in adults; very dry mouth, skin and mucous membranes; little or no urination - any urine that is produced will be darker than normal; sunken eyes; shriveled and dry skin that lacks elasticity and doesn't "bounce back" when pinched into a fold; in infants, sunken fontanels - the soft spots on the top of a baby's head; low blood pressure; rapid heartbeat; rapid breathing; no tears when crying; fever; and, in the most serious cases, delirium or unconsciousness.

Unfortunately, thirst isn't always a reliable gauge of the body's need for water, especially in children and older adults. A better indicator is the color of the urine: clear or light-colored urine means you're well hydrated, whereas a dark yellow or amber color usually signals dehydration.

When to see a doctor? If you're a healthy adult, you can usually treat mild to moderate dehydration by drinking more fluids, such as water or a sports drink. Get immediate medical care if you develop severe signs and symptoms such as extreme thirst, a lack of urination, shriveled skin, dizziness and confusion.

Treat children and older adults with greater caution. Call the doctor right away if the following are observed:

. Develops severe diarrhea, with or without vomiting or fever;

. Has bloody or black stool;

. Has had moderate diarrhea for 24  hours or more;

. Can't keep down fluids;

. Is irritable or disoriented and much sleepier or less active than usual;

. Has any of the signs or symptoms of mild or moderate dehydration.

Call an emergency service or take to the nearest hospital a child or older adult that shows symptoms of severe dehydration. But you can help prevent severe dehydration by carefully monitoring someone who is sick and giving fluids, such as an oral rehydration solution, at the first sign of diarrhea, vomiting or fever and by encouraging children to drink plenty of water before, during and after exercise.

Dehydration occurs when there isn't enough water to replace what's lost throughout the day. Your system literally dries out. Sometimes dehydration occurs for simple reasons: You don't drink enough because you're sick or busy, or because you lack access to safe drinking water when you're traveling, hiking or camping.

Other dehydration causes include:

. Diarrhea, vomiting. Severe,  acute diarrhea - that is, diarrhea that comes on suddenly and  violently - can cause a tremendous loss of water and electrolytes in a short amount of time. If you have vomiting along with diarrhea, you lose even more fluids and minerals. Children and infants are especially at risk. Diarrhea may be caused by a bacterial or viral infection, food sensitivity, a reaction to medications or a bowel disorder.

. Fever. In general, the higher your fever, the more dehydrated you may become. If you have a fever in addition to diarrhea and vomiting, you lose even more fluids.

. Excessive sweating. You lose water when you sweat. If you do vigorous activity and don't replace fluids as you go along, you can become dehydrated. Hot, humid weather increases the amount you sweat and the amount of fluid you lose. Preteens and teens who participate in sports may be especially susceptible, both because of their body weight, which is generally lower than that of adults, and because they may not be experienced enough to know the warning signs of dehydration.

. Increased urination. This may be due to undiagnosed or uncontrolled diabetes. Certain medications, such as diuretics and some blood pressure medications, also can lead to dehydration, generally because they cause you to urinate or perspire more than normal.

Dehydration can lead to serious complications, including:

. Heat injury.  If you don't drink enough fluids when you're exercising vigorously and perspiring heavily, you may end up with a heat injury, ranging in severity from mild heat cramps to heat exhaustion or potentially life- threatening heatstroke.

. Swelling of the brain (cerebral edema). Sometimes, when you're getting fluids again after being dehydrated, the body tries to pull too much water back into your cells. This can cause some cells to swell and rupture. The consequences are especially grave when brain cells are affected.

. Seizures. Electrolytes - such as potassium and sodium - help carry electrical signals from cell to cell. If your electrolytes are out of balance, the normal electrical messages can become mixed up, which can lead to involuntary muscle contractions and sometimes to a loss of consciousness.

. Low blood volume shock  ( hypovolemic shock). This is one of the most serious, and sometimes life-threatening, complications of dehydration. It occurs when low blood volume causes a drop in blood pressure and a drop in the amount of oxygen in your body.

. Kidney failure. This potentially life-threatening problem occurs when your kidneys are no longer able to remove excess fluids and waste from your blood.

. Coma and death. When not treated  promptly and appropriately, severe dehydration can be fatal.

(mayoclinic.org)