Morning bad breath usually has the following factors: 1. For those who brush their teeth regularly, there is no inflammation or infection in the mouth, morning bad breath is due to the fermentation of bacteria in the mouth overnight, producing certain anaerobic bacteria, anaerobic bacteria will release unpleasant odors, and patients will feel bad breath in the morning, which can be immediately relieved by brushing teeth, rinsing mouth and drinking water. 2. If not relieved by the above methods, we should check whether there is Infection in the mouth, such as gingivitis, periodontitis, etc., because when there is inflammation and infection in the mouth will continue to release unpleasant odor, which will make you feel like you have bad breath all the time. This is when you need to take certain medications, such as anti-anaerobic drugs and anti-inflammatory drugs, such as taking metronidazole, ofloxacin, etc., to treat gum and oral mucosal ulcers at the same time can relieve bad breath. If you have stomach fire and liver fire, you may also feel bad breath noticeably in the morning when you wake up and it lasts for 1-2 hours. If there is no obvious sign of improvement even after brushing your teeth, you need to go to the hospital to find out if it is caused by stomach fire and liver fire.