Table 2: Signs of dehydration

From: Water as an essential nutrient: the physiological basis of hydration

Signs of mild-to-moderate dehydrationSigns of severe dehydration
Dry, sticky mouthExtreme thirst
Sleepiness or tirednessExtreme fussiness or sleepiness in infants and children; irritability and confusion in adults
ThirstVery dry mouth, skin and mucous membranes
Decreased urine outputLack of sweating
Few or no tears when cryingLittle or no urination—any urine that is produced will be dark yellow or amber
Muscle weaknessSunken eyes
HeadacheShrivelled and dry skin that lacks elasticity and does not ‘bounce back’ when pinched into a fold
Dizziness or light-headednessIn infants, sunken fontanels—the soft spots on the top of a baby's head
 Low blood pressure
 Rapid heartbeat
 Fever
 Delirium or unconsciousness