Everything that i eat or drink except water has a bitter taste.this started a few days ago. i gargled with listerine and salt water. i brushed my tongue. i ate a piece of pie and it still tasted bitter. why could it be?

This : This problem is actually not too uncommon and has a huge differential of potential causes such as: - nasal drainage - nasal polyps - bad tooth - gastroesophageal reflux - salivary gland obstruction/ dry mouth - medications - a neurological problem with the taste receptors and that's just scraping the surface! you should see your doctor or an otolaryngologist (ear, nose and throat specialist) for an exam and a work-up. Hopefully, if they can find the cause, they can fix the problem. Good luck!

Bitter taste: Certain medications cause a bitter taste as well as infections. There may be a systemic problem. A suggestion would be to identify when this problem developed, note any changes in diet or use of over the counter medication and discuss this with your primary care doctor.

Many possibilities: This could be coming from a variety of causes. You need to be evaluated by doctors who understand the implications of changes of taste sensation. An ENT might be a good place to start.