What causes bad saliva?

Bad saliva can be caused by various factors, including dehydration, poor oral hygiene, and certain medical conditions such as dry mouth (xerostomia) or infections. Diet and lifestyle choices, such as high sugar intake or smoking, can also contribute to saliva quality. Additionally, medications that cause dry mouth as a side effect can affect saliva production and composition, leading to an unpleasant taste or odor. Maintaining proper hydration and oral care can help mitigate these issues.