Of course, bad breath can be caused by a variety of things. Diet is a major factor, with temporary unpleasant odors being caused by the well-known work of onions and garlic. "Morning breath" is caused by the mouth being closed and dry during sleep, so you can't benefit from the cleaning effects of saliva. Symptoms from these causes can usually be handled by cleaning the mouth and tongue.
However, chronic bad breath can be a sign of a more serious problem. Periodontal disease or dental work that is in need of restoration can cause halitosis that is relatively constant. Gum, mints and mouthwashes will only mask it temporarily. The dentist can help you find the root of the problem.
Some dentists have a device called a Halimeter to measure bad breath. They also have products, such as BreathRx designed to help you fight bad breath at home. So visit the dentist, fix that bad breath and move your hand away from your mouth.