Why does saliva turn yellow during sleep at night?
This morning when I woke up, I noticed yellow saliva on my pillow from sleeping at night. I would like to ask why this happens?
Doctor's answer (1)
The change of saliva color to yellow at night may be related to multiple factors. The following are some possible causes:
1. Oral hygiene issues: Poor oral hygiene is a common cause. For example, failure to clean teeth promptly may lead to bacterial growth and increased decomposition products in saliva, resulting in yellow discoloration.
2. Dietary factors: Consuming excessive spicy foods before bedtime, such as chili peppers or onions, may stimulate salivary gland secretion. Additionally, consuming large amounts of foods containing yellow pigments, such as mangoes or oranges, may also cause yellow saliva.
3. Improper sleeping posture: Prolonged maintenance of a single sleeping position may exert pressure on the face, causing excessive salivary secretion and resulting in yellow saliva.
4. Medical conditions: Diseases of the hepatobiliary system may also affect saliva color, as abnormal bile excretion may allow bilirubin and other substances to influence saliva color via the bloodstream.
5. Oral ulcers: Oral mucosal injuries may stimulate salivary gland secretion and mix with inflammatory factors, causing yellow-colored saliva.
