Colds with bloody sputum are considered to be related to rupture of the respiratory mucosa, bronchial dilatation, bronchial tuberculosis or pulmonary tuberculosis, lung tumors and other causes. 1. Respiratory mucous membrane rupture: If coughing up bloody sputum is caused by a simple cold, it may affect the nasal cavity, or the pharynx and other respiratory tracts with mucous membrane damage, and the rupture of submucous capillaries. 2. Bronchial dilatation: If a cold is accompanied by bronchial dilatation, it can also cause coughing up bloody sputum, often accompanied by coughing up pus sputum, pestle fingers and other symptoms. 3. Bronchial tuberculosis or tuberculosis of the lungs: patients suffering from bronchial tuberculosis or tuberculosis of the lungs, after the cold may cause tuberculosis aggravation, resulting in coughing up bloody sputum symptoms. 4. Lung tumors: Lung tumors may appear persistent or intermittent sputum with blood or a small amount of hemoptysis. There may be other reasons for coughing up bloody sputum, so we suggest you go to the hospital in time to get a clear idea of the cause of coughing up bloody sputum, so as to avoid delaying your condition.