When your body loses dramatically more fluids than you take in, or drink, you will suffer from dehydration. Mild to moderate dehydration is treated by increasing the amount of fluids you drink; however, severe dehydration is a life threatening condition that warrants a trip to the emergency room. Sweating a lot, vomiting, diarrhea and a fever are all causes of dehydration. The elderly and young children are at an increased risk of suffering from dehydration, but the condition can affect anyone.
Check the color of your urine. Dark urine is a sign of dehydration. Also, you may be dehydrated if you aren't urinating at all or as much as normal, notes MedlinePlus, a service of the National Institutes of Health. Failure to urinate for eight hours or having extremely dark or amber colored urine are signs of severe dehydration that requires a trip to the emergency room.
Pay attention to your thirst. If you are thirsty or if your mouth is sticky and dry, you are dehydrated, notes KidsHealth, an information website sponsored by the Nemours Foundation. Severe thirst is a sign of severe dehydration, which needs prompt medical treatment.
Think about how you feel. Dehydration will make you tired and weak. Dizziness, headache, lightheadedness and delirium are also signs of dehydration. Severe dehydration may result in a loss of consciousness.
Pinch the skin on the back of your hand. If the skin seems to stick together, you are severely dehydrated and need to head to the hospital. If the skin slowly moves back to its original position, you are mildly to moderately dehydrated and need to drink fluids immediately. If the skin bounces back to its original position quickly, you aren't dehydrated.
Look at your eyes. If they are sunken in, you are severely dehydrated and need immediate fluid replacement.