Home > Encyclopedia of Children's Health > Thumb Sucking

Definition

Thumb sucking is the childhood habit of putting the thumb in the mouth for comfort or to relieve stress.

Description

About half of all children suck their thumbs during infancy, with most starting in the first weeks of life. Ultrasound pictures of intrauterine life have even shown fetuses sucking their thumbs. One way that infants explore their world is by putting objects in their mouths and sucking on them. Thumb sucking appears to be a natural habit of children in all parts of the world. Sucking the thumb is soothing for a small child, and many children continue this habit for comfort and security into the early school years. Thumb sucking is most prevalent in children under two, and most children give up the habit on their own by age four.

Thumb sucking by itself is not...