I have a 7yr old son who is asthmatic.has had a cough for 2 days and he says his chest hurts when he coughs. no fever.what could this possibly be?

An asthma attack: Check with your pediatrician to go over your asthma action plan utilizing rescue and maintenance medications for inhalation. This will help the cough and chest pain caused by inflammation/constriction of his airways. An exam can be performed to rule out any bacterial infection vs viral illness or other external triggers.

Asthma flare-up: It could just be an asthma exacerbation, which can be caused by infection (even without fever).