There are many factors that may cause patients to have blood clots in morning sputum, which may be caused by the following causes: 1. Due to diseases such as bronchial dilatation, patients may have cough and shortness of breath in addition to blood clots in sputum. 2. Due to inflammation of trachea and lung, patients may cough when there is inflammation of trachea and lung, which may damage the mucous membrane of the respiratory tract and cause blood vessels to rupture and cause bleeding in the process of violent coughing. 3. 3. If the patient has blood clots in the sputum for a long time and is accompanied by symptoms such as wasting and hoarseness, he/she should be highly alert to malignant diseases such as bronchopulmonary cancer and should go to the hospital for CT or MRI examination to clarify the cause.