Bad odour from mouth can be really embarrassing. It could be because of deposits in your mouth, cavities, food habits, other tobacco or cigarette habits and also due to gastric problem. But bad breathe just after waking up in the morning is normal. My suggestion would be get checked by a dentist for any cavities or deposits that might be remaining. If not then check your food habits if it contains too much of onions, garlic etc. Try to limit those. Also check if you have any gastric problem.

Bad breath after waking from sleep is normal and physiologic. If you have the same problem other times then it's a matter of concern. Reasons could be multiple. I'll advise you to do lukewarm salty water gaurgle 3-5 times a day for a week.... And followup of there's any improvement Quit habits ( smoking, tobacco, alcoholism, heavy tea/ coffee intake etc) immediately Get cavity ( if you have any) treated. Sometimes bad breath is also associated with gastrointestinal problems/ acidity/ peptic ulcers etc. Get in habit of flossing once daily Also use chlorhexidine mouthwash once In two days ( donot overuse)