That's pretty low. Out of all your electrolytes, potassium is the one you simply don't want to mess with, as it can cause heart problems even in an otherwise healthy person, and doesn't need to be too far off to do so. You really need to be 3.0+ at minimum. Your doc should have rx'ed you some potassium pills to increase that level. Are you on Lasix (furosemide?) - if so, that could be contributing to low potassium. That is something you really need to fix though. If you don't have kidney problems, drink some OJ, eat a banana, and call your doc to get some potassium pills (they are huge pills unfortunately, sorry, but it is something you want to take care of right away)
