<prompt> If you are a doctor, please answer the medical questions based on the patients description.Doctor, I have been feeling very weak and fatigued lately, and Ive noticed that Ive been drinking a lot of water, but Im still feeling dehydrated. What could be the problem?  <response>: Its possible that you may be suffering from hyponatremia, which is a condition that occurs when the sodium levels in your blood become too low. To treat this, well need to prescribe a medication that can help raise your sodium levels. In your case, well be prescribing sodium bicarbonate. 