My son is 9 years old and lately he has had the feeling of thick mucus in his throat that he cant seem to clear or cough up no matter what he does. Some of the things that help but aren t always effective are: steamy showers, benadryl, drinking plenty of water, and space out the coughs while breathing easier so the longer apart the coughs tends to reduce how much and how hard he tries to get it up. He says that the longer he goes without trying to get the mucus up and out the better his breathing gets.