For frequent whitening of the mouth and lips, the usual causes are as follows: 1. The most common factors are cardiogenic diseases, such as chronic cardiac insufficiency, chronic heart failure, coronary artery disease, unstable angina, myocarditis, rheumatic heart disease, and hypertrophic obstructive cardiomyopathy. These conditions can lead to ischemia and lack of oxygen in cardiac muscle cells, which can cause white lips. 2. For chronic respiratory diseases, such as chronic bronchitis, chronic bronchiectasis, chronic obstructive emphysema, chronic pulmonary heart disease, and pulmonary hypertension. These conditions can lead to a decrease in arterial oxygen saturation, low partial pressure of oxygen and high partial pressure of carbon dioxide, which can also lead to white lips. 3. For peripheral metabolic diseases, such as hypothyroidism, adrenocortical insufficiency or chronic anemia, long-term infection, these factors can also lead to white lips.