My 4 year old went through that and his Doctor recently diagnosed him with asthma. The doctor told me when he was a year old he might have asthma, but it was too early to diagnose it. Has she had this problem before? My son had mucus on his lungs when he was less than a month old, then at a year old he got bronchitis. Last year he had a really bad cough and I put him back on his inhaler and it cleared up, then about two months ago he got a cold and then came the really bad cough. He also had mucus on his lungs again. We put him back on the inhalers and it cleared up. It seems that his colds cause his asthma to flare up.