One of the things that can complicate asthma for those people who suffer from this chronic condition is the deposition of mucus in the throat. In addition to constriction of the airways, phlegm or mucus in the respiratory tracts can make asthma attacks much more serious. Lemon has the ability to cut through mucus and eliminate it from the respiratory tracts, thus leaving the airways open. Lemon also has certain antiseptic qualities, which makes it an effective remedy for whatever underlying infection may have been causing the mucus to form in the first place.