What causes a thick, yellow tongue coating?

Generally, thick yellow tongue coating may be caused by dietary factors, unhealthy lifestyle habits, indigestion, excessive stomach fire, or damp-heat in the liver and gallbladder. It is recommended to seek timely medical advice and undergo treatment under a physician's guidance. Detailed analysis is as follows:

1. Dietary Factors

Consuming large amounts of spicy or greasy food in a short period can increase the digestive burden on the gastrointestinal tract, leading to dysfunction of the spleen and stomach's transformation and transportation functions. This dysfunction results in internal damp-heat, which steams and manifests on the tongue surface, causing thick yellow tongue coating. It is advisable to adjust dietary habits, maintain a light diet, and consume more vegetables and fruits.

2. Unhealthy Lifestyle Habits

Long-term late-night activities and irregular作息 (作息 should be translated as作息 habits or sleep patterns) can disrupt the body's normal metabolism and organ functions. The spleen and stomach do not receive adequate rest at night, resulting in weakened transformation and transportation abilities and internal dampness accumulation, which leads to thick yellow tongue coating. Developing good sleep habits, going to bed early, and waking up early can help avoid staying up late.

3. Indigestion

Indigestion often results from insufficient gastrointestinal motility, irregular eating habits, or overeating. Slowed intestinal peristalsis causes food to remain in the gastrointestinal tract for prolonged periods, preventing normal digestion and emptying, which leads to food stagnation and fermentation, manifesting as thick yellow tongue coating. Symptoms such as abdominal distension, abdominal pain, and loss of appetite may also occur. Patients can use medications such as Jianwei Xiaoshi Tablets (Digestive Aid Tablets), Domperidone Tablets, or Baohe Pills under a physician's guidance.

4. Excessive Stomach Fire

Excessive stomach fire may result from excessive consumption of spicy or hot-natured foods, emotional stress, or Qi stagnation transforming into fire. When stomach fire becomes excessive, the stomach's digestive function becomes hyperactive, and heat pathogens rise upward into the mouth, scorching the tongue coating and causing thick yellow tongue coating. Symptoms such as bad breath, swollen and painful gums, and dry, hard stools may also occur. Patients should follow medical instructions to use medications such as Huanglian Shangqing Pills, Niuhuang Qingwei Pills, or Huoxiang Qingwei Capsules to alleviate discomfort.

5. Damp-Heat in the Liver and Gallbladder

Damp-heat in the liver and gallbladder typically results from external contraction of damp-heat pathogens or long-term emotional depression. Liver Qi fails to course smoothly, and bile excretion becomes impaired, leading to damp-heat accumulation in the liver and gallbladder. This damp-heat ascends along the meridians to the tongue surface, causing thick yellow tongue coating. Symptoms such as distending pain in the hypochondrium, bitter taste in the mouth, dry throat, red and painful eyes may also occur. Patients can take Longdan Xiegan Pills, Yin Zhi Huang Oral Liquid, or Xiaoyan Lidan Tablets under a physician's recommendation.

In daily life, maintaining good oral hygiene, brushing teeth properly in the morning and evening, and rinsing the mouth after meals are important. Additionally, engaging in appropriate physical exercise helps strengthen the body and promote gastrointestinal motility.