The common reasons for getting up every morning with bitter mouth are as follows: First, it may be caused by poor oral hygiene conditions, gum and periodontal diseases. Usually, there is a large amount of calculus around the gums to stimulate the gums, and it is easy to produce redness, swelling and overflowing pus, which usually causes bad taste in the mouth and the phenomenon of bitter mouth in the morning. Second, bitter mouth in the morning may also be caused by systemic diseases, such as liver and gallstones or poor liver and kidney function, are prone to produce the phenomenon of bitter mouth. Thirdly, the bitterness of mouth in the morning may also be caused by a large number of dental caries and the dysbiosis of the oral flora, resulting in the phenomenon of bitterness. Fourth, the bitterness of the mouth every morning may be caused by salivary gland diseases, such as dry mouth, salivary gland saliva secretion or salivary gland tumor, salivary gland stones, which may lead to bitter taste in the mouth.