Bad colds, allergic reactions, and coming into contact with an irritant generally cause excessive mucus, notes WebMD. In some people, drinking milk also causes excessive mucus production.
Over-the-counter medications and natural remedies can reduce excessive mucus, states WebMD. Antihistamines block allergic reactions from occurring, preventing the release of excess thin mucus from the nose. Decongestants reduce blood flow to the nose, which causes less mucus production; however, this may make the mucus thicker.
A natural method of removing mucus is nasal irrigation using a neti pot, bulb syringe or squeeze bottle to shoot saline solution into the nasal cavity to rinse it out, advises WebMD. Performing nasal irrigation too frequently can increase the chance that an infection develops.