Options for eliminating excess phlegm in the throat include treating the underlying condition, reducing post-nasal drip and thinning the mucus, according to WebMD. Propping the head up with pillows at night helps to prevent the mucus from pooling at the back of the throat.
Infections are a common cause of excess phlegm, and treating the infection eliminates the problem, indicates WebMD. If the infection is bacterial in nature, an antibiotic helps to clear the bacteria so that the mucus drains normally. Viral infections, including the common cold, do not respond to antibiotics.
Postnasal drip is the most common cause of excess phlegm in the throat, reports WebMD. Options to reduce this cause include antihistamines and decongestants. Some of the older types of antihistamines make the problem worse. Diphenhydramine and chlorpheniramine tend to dehydrate the mucus, which makes it thicker and more irritating to the throat. If postnasal drip is due to allergies, reducing the allergens in the room is helpful.
Saline rinses in the nose help to thin the material so it is able to move through the throat. Guaifenesin, an over-the-counter medicine, is available in tablets and syrups to help thin the mucus. Operating a vaporizer in the room to increase the moisture in the air decreases the thick mucus in the throat, according to WebMD.