White and thick tongue at the root may be related to kidney yang deficiency (lack of yang energy in the kidneys) and phlegm-dampness stagnation. According to Traditional Chinese Medicine (TCM), the tip of the tongue belongs to the heart, the back of the tongue belongs to the lungs, the middle of the tongue belongs to the spleen and stomach, the edges of the tongue belong to the liver and gallbladder, and the root of the tongue belongs to the kidney. 1. Kidney yang deficiency: In addition to the white and thick tongue coating, kidney yang deficiency may also lead to mental weakness, coldness in the waist and knees, coldness in the limbs (fear of cold, cold limbs), and whiteness (white and lack of luster) or sallowness of the face. 2. phlegm-dampness stagnation: phlegm-dampness stagnation will not only show the root of the tongue coating white thick, but also may be accompanied by heavy limbs (limb weakness, sinking), lower limb edema, less food and greasy mouth, chest and epigastric congestion, local round tough lumps and other symptoms. The white-thickness of the root of the tongue needs to be analyzed in combination with other clinical manifestations in order to determine the cause of the disease. If you feel unwell, it is recommended that you consult a traditional Chinese medicine practitioner in a timely manner so as to avoid any delay in the treatment of your condition.