Calcified foci in the left pleura may be caused by chronic inflammatory stimuli such as chronic pleurisy. Due to long-term inflammatory stimulation, large amounts of inflammatory metabolites are produced, and metabolite deposition in the pleura can produce calcified foci in the pleura; chronic pleurisy, such as tuberculous pleurisy, may produce chronic pathogenic microbial stimulation, resulting in the production of calcified foci in the left thoracic pleura. The appearance of calcified foci does not necessarily mean that the disease is present, but may be the scar left over from the past disease; most of the calcified foci themselves do not cause harm, if the calcified foci are small, relatively fixed, without obvious increase in size, the patient has no discomfort, can not be treated, and can be closely observed. If the foci of calcification continue to increase in size, it is recommended that the patient should consult a doctor in time to check whether there is a new disease or whether the existing disease has not been cured.