Early Symptoms of Dehydration
Symptoms and signs of dehydration can be minor, such as increased thirst, or severe and life-threatening, depending on the extent of the dehydration.
The early symptoms of dehydration are
- thirst, and
- reduced urine output and darkening of the urine.
As dehydration progresses, other symptoms develop, including
- dry mouth,
- muscle cramps, and
Quick GuideDehydration: Causes, Symptoms & Tips to Stay Hydrated
- The body needs water to function.
- Dehydration occurs when water intake is less than water loss.
- Symptoms range from mild to life-threatening.
- The young and the elderly are especially susceptible to dehydration.
What is dehydration?
Water is a critical element of the body, and keeping the body adequately hydrated is a must to allow the body to function. Up to 75% of the body's weight is made up of water. Most of the water is found within the cells of the body (intracellular space). The rest is found in the extracellular space, which consists of the blood vessels (intravascular space) and the spaces between cells (interstitial space).
Dehydration occurs when the amount of water leaving the body is greater than the amount being taken in. The body is very dynamic and always changing. This is especially true with water in the body. We lose water routinely when we:
- breathe and humidified air leaves the body (this can be seen on a cold day when you can see your breath in the air, which is just water that has been exhaled);
- sweat to cool the body; and
- eliminate waste by urinating or having a bowel movement.
In a normal day, a person has to drink a significant amount of water to replace this routine loss.
The formula for daily fluid requirements depends upon an individual's weight. Normally, fluid and weight are calculated using the metric system; however, below is the approximation in imperial (American) units.
|Body weight||Daily fluid requirements (approximate)|
|10 pounds||15 ounces|
|20 pounds||30 ounces|
|30 pounds||40 ounces|
|40 pounds||45 ounces|
|50 pounds||50 ounces|
|75 pounds||55 ounces|
|100 pounds||50 ounces|
|150 pounds||65 ounces|
|200 pounds||70 ounces|
If you would like to calculate your body weight and daily fluid requirements using the metric system, please use this formula.
- For the first 10kg (kilogram) of body weight the daily fluid intake required is 100cc (or mL) per kg.
- For the next 10kg of body weight, the fluid required is an additional 50 cc/kg.
- For every additional kg of body weight, an additional 10cc/kg is required
This is the basic body requirement. More fluid would be needed to replace excess sweating from exercise or fever, fluid loss from vomiting, and diarrhea or increased urine production.
Medically Reviewed by a Doctor on 10/5/2016