DEHYDRATION
Dehydration occurs when more water and fluids leave the body than enter it. Even low levels of dehydration can cause headaches, lethargy, and constipation.
The human body is roughly 75 percent water. Without this water, it cannot survive. Water is found inside cells, within blood vessels, and between cells.
CAUSES
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.
- Fever. In general, the higher your fever, the more dehydrated you may become. The problem worsens if you have a fever in addition to diarrhea and vomiting.
- 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.
- 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 more.
SIGNS AND SYMTOMS
The body’s initial responses to dehydration are thirst to increase water intake, and decreased urine output to try to conserve water loss. The urine will become concentrated and more yellow in color.
As the level of water loss increases, more symptoms can become apparent. The following are further signs and symptoms of dehydration.
- Dry mouth
- Eyes stop making tears
- Sweating may stop
- Muscle cramps
- Nausea and vomiting
- Heart palpitations
- Lightheadedness (especially when standing)
- Weakness
- Decreased urine output
The body tries to maintain cardiac output (the amount of blood that is pumped by the heart to the body); and if the amount of fluid in the intravascular space is decreased, the body compensates for this decrease by increasing the heart rate and making blood vessels constrict to try to maintain blood pressure and blood flow to the vital organs of the body. The body shunts blood flow away from the skin to internal organs, for example, the brain, heart, lungs, kidneys, and intestines; causing the skin to feel cool and clammy. This coping mechanism begins to fail as the level of dehydration increases.
With severe dehydration, confusion and weakness will occur as the brain and other body organs receive less blood flow. Finally, coma, organ failure, and death eventually will occur if the dehydration remains untreated.
DIAGNOSIS
Your doctor can often diagnose dehydration on the basis of physical signs and symptoms. If you’re dehydrated, you’re also likely to have low blood pressure, especially when moving from a lying to a standing position, a faster than normal heart rate and reduced blood flow to your extremities.
To help confirm the diagnosis and pinpoint the degree of dehydration, you may have other tests, such as:
- Blood tests. Blood samples may be used to check for a number of factors, such as the levels of your electrolytes — especially sodium and potassium — and how well your kidneys are working.
- Urinalysis. Tests done on your urine can help show whether you’re dehydrated and to what degree. They also can check for signs of a bladder infection
TREATMENT
The only effective treatment for dehydration is to replace lost fluids and lost electrolytes. The best approach to dehydration treatment depends on age, the severity of dehydration and its cause.
For infants and children who have become dehydrated from diarrhea, vomiting or fever, use an over-the-counter oral rehydration solution. These solutions contain water and salts in specific proportions to replenish both fluids and electrolytes.
Children and adults who are severely dehydrated should be treated by emergency personnel arriving in an ambulance or in a hospital emergency room. Salts and fluids delivered through a vein (intravenously) are absorbed quickly and speed recovery