A growth spurt is a period when a child's height rapidly increases. Growth spurts are most obvious when a child is an infant (ages 1 month through 11 months) and during the teen years (starting at about age 11 for girls and at about age 13 for boys).

The signs of a growth spurt include:

• Increased appetite. A child's nutritional needs increase before and during periods of rapid growth.
• An increase in bone and muscle growth.
• An increase in the amount of fat stored in the body.

Growth spurts can last days to years.