Sometimes delayed development has a medical cause, such as complications of a premature birth or a genetic condition, like Down’s syndrome. It could also be the result of a serious illness or accident.

Speech and language delay might stem from a hearing impairment or a problem with the larynx, throat, or nasal or oral cavity. Difficulties with communication might be related to a problem with the central nervous system. Most often, though, no specific medical cause can be found to explain developmental delays.