The severity of dehydration - i.e. mild, moderate or severe dehydration - can be determined via signs and symptoms.

A mildly dehydrated child with about a 5% loss in body weight will be pretty much asymptomatic except for a decrease in urine output and increased thirst.

With moderate dehydration (i.e. 10% loss), heart rate increases and blood pressure may be low normal; remember vital signs changes are a relatively late findings and are very, very concerning. Other signs of moderate dehydration include: decreased urine output, dry mucous membranes, sunken anterior fontanel and eyes, decreased skin turgor, decreased tears, and a prolonged capillary refill time.

If the child is severely dehydrated, all of these clinical manifestations are exacerbated and you will note decreased BP, tachycardia, poor perfusion, and decreased LOC - all the typical signs of shock. The majority of infants and children with 15% dehydration will need to be managed in an ICU setting.