The nose and sinuses naturally secrete mucus, and lots of it! A normal person secretes over 1 liter of mucus per day. Typically, this mucus continuously flows from the nose into the throat, and is swallowed subconsciously. Postnasal drip refers to the sensation of mucus draining from the back of the nose into the throat. Patients feel like this mucus is always “stuck” back there and not moving. This symptom has a variety of causes. In some cases, there is actually increased production of mucus. This can be caused by allergies or viral illnesses. In other cases, the consistency of the mucus changes and is more thick and irritating. This can occur due to inflammation from chronic sinusitis, dry air, hormone changes, medication side effects, acid reflux, and even food allergy. Sometimes it’s not a mucus issue at all, but rather inflammation or irritation in the throat that causes this sensation.