Drink lots of water. The University of Texas Health Science Center at San Antonio recommends 6 to 8 eight-ounce glasses of water every day for professional voice users. The general rule of thumb is to drink water until your urine is pale in color. Staying properly hydrated keeps the mucus layer on your vocal cords thin.
Avoid caffeine and alcohol. Caffeinated and alcoholic beverages have a dehydrating effect that robs your entire body of moisture, including your vocal cords, which leads to thickening of the mucus. Limit your intake as much as possible and drink more water to counteract the dehydrating effects when you do consume caffeine or alcohol.
Use a humidifier. Dry air due to climate conditions, indoor heating and air conditioning dries your vocal cords, again contributing to excess mucus. Run a humidifier at night while you sleep.
Talk to your doctor about reflux disorders and medications -- some medications will contribute to the problem and some may improve it. One possible medical cause of thick mucus in the vocal cords is acid reflux -- either gastroesophageal reflux disease (GERD) or laryngopharyngeal reflux disease (LRD). Reflux can cause a mucus problem even if you don't experience heartburn, so talk to your doctor about diagnosis and treatments. Some medications contribute to excess mucus in the vocal cords by drying the vocal tract. Some of them include antihistamines and decongestants, but ask your doctor for information and advice about specific drugs.