Have had post nasal drip for years, weird taste all the time. how to tell the difference between csf and post nasal drip?

Sinusitis : Sinusitis or inflammation of the sinuses can cause headaches. Postnasal drip causes nausea, poor appetite, and weight loss. A CSF leak leaves a salty taste in the back of the throat and/or leaks clear fluid from a single nostril. The leak is worse with straining or bending over. See an ear nose and throat physician or otolaryngologist to monitor your symptoms.