I have a bitter taste in my mouth i don't know why every time i drink water it worsens it started yest. could it be any medical condition?

Gum disease: Bitter taste can be a sign that you are at risk for, or already have, gum disease. The bacteria, along with mucus and other particles, constantly form a sticky, colorless toxic “plaque” on teeth causing the gums to become inflamed and to easily bleed. This condition should be checked by a dentist. It is a painless condition, but can induce serious complication.

Bad taste: Probably bacterial infection of tooth/teeth and/or gum tissues/bone. Yes, there are systemic causes for your symptoms, but infection is the most probable. You need to find the best Dentist that you can. If you have wide spread infection, treatment is most likely to be complex.