Black and purple tongue is related to trauma to the tongue, medicinal food staining the coating, hyperthermia, and Qi stagnation and blood stasis (stagnation of blood due to lack of circulation of Qi). 1. If there are limited black and purple spots on the tongue, and there is a recent history of accidental biting or burning of the tongue without other uncomfortable symptoms, it is petechiae formed due to localized mucosal bleeding. 2. After consuming black mulberry or medicinal food such as Liu Wei Di Huang Pills, the tongue will be dyed black and purple, and there are no other uncomfortable symptoms, you can use too much water or gargle more to make the tongue color return to normal. 3. If the body’s heat and toxin is overbearing, the blood and qi are congested, and blood heat fills the tongue, resulting in a black and purple tongue, accompanied by red face and eyes, high fever and dizziness, sore throat, dry mouth and bitterness, short and red urination (small amount of urination, dark yellow color), and dry and knotty stools, and other symptoms of heat and toxin blazing (the body’s fire is overbearing). 4. If the body is liver depression and stagnation of qi (liver qi and blood transportation is not smooth, emotional depression), or cold condensation stagnation of qi, or qi deficiency, etc., resulting in poor qi and blood operation, stagnation of blood stagnation in the tongue will be manifested as a black and purple tongue, accompanied by the face of the stagnation of the color of darkness, fatigue, tiredness and weakness, irritability, chest tightness, chest pain, menstrual cramps, petechiae, tingling and other obvious symptoms. If you have abnormal tongue, you should consult a doctor in time and take treatment under the guidance of a professional doctor to avoid delaying your condition.