Oct 21, 2013
These are the most RELIABLE symptoms and signs of dehydration:
1. Sudden loss of weight (hours/few days). Even if you exercise regularly, it is not likely you will lose several pounds of weight in a day or two.
2. Decreased amount of urine. Less than 200 mL of urine in the morning after >6 hours sleep can speak for dehydration, even if your urine is completely clear ("white," translucent).
3. Dark urine. A small amount of dark yellow or brown urine speaks for dehydration. Other causes of dark urine:
- vitamin supplements (vitamin B complex) - bright yellow urine
- iron supplements: greenish urine
- certain antibiotics, for example rifampin (for tuberculosis)
- certain artificial food dyes
- beet root, blackberries, rhubarb: reddish urine (in some people)
- blood: red urine
- kidney disease
4. Decreased skin elasticity. When you pinch and release the skin on the back of your hand, it should flatten immediately; any delay in skin flattening speaks for dehydration. This test obviously doesn't work in people who have wrinkled skin even when well hydrated; it may also not work in obese individuals in whom the skin can flatten quickly even when dehydrated. Decreased skin elasticity probably appears only when you miss more than one liter of water in your body.
5. Dry mouth (and later, lips). Also not an early, but when you miss more than 1-2 liters of water, you wil very likely experience dry mouth.
When dehydrated, you may or may not experience some other known symptoms, but they are NOT RELIABLE (can be absent or caused by many other conditions):
- Loss of appetite
- Absent sweating. This is a tricky one. You walk in a hot, dry, windy way without a drop of a sweat, because the wind blows it away before you notice it. On the other hand, when you are severely dehydrated, you are so water deficient that you cannot sweat any more. This may result in quick rise of your body temperature (heat stroke), which is a medical urgency.
- In severe dehydration, you may experience seizures or fall into coma.
- I almost forgot thirst. Thirst is very unreliable symptom of dehydration. You can feel thirsty and are not dehydrated at all or be severely dehydrated and not feel thirst at all.