A fontanelle, also known as a "soft spot," is an anatomical feature of the infant human skull comprising soft membranous gaps (sutures) between the bones of the skull. There are two fontanelles in an infants skull, which are covered by tough membranes that protect the underlying soft tissues and brain:

• Anterior fontanelle: This is the junction where the two frontal and two parietal bones meet. The anterior fontanelle remains soft until about 18 months to 2 years of age. Doctors can assess if there is increased intracranial pressure by feeling the anterior fontanelle.

• Posterior fontanelle: This is the junction of the two parietal bones and the occipital bone. The posterior fontanelle usually closes first, before the anterior fontanelle, during the first several months of an infants life.

Fontanelles are important for the normal growth and development of a babys brain and skull. Health teams check a babys fontanelles during routine visits, and parents can gently touch their babys fontanelles as long as they are gentle. A normal fontanelle should feel soft and flat, and if it changes or feels different, it may be a sign that the babys health needs to be checked. A tense or bulging fontanelle may be a sign of a number of serious but rare conditions, including meningitis or encephalitis (infections in the brain), cerebral hemorrhage (bleeding in the brain), hydrocephalus, an abscess, or another cause of increased pressure in the brain.