Hi yukinori, Thanks for visiting HCM. coughing up of blood may be a manifestation of air way injury due to violent cough. or else may signify underlying disease. I advise you to go for chest xray done for your mother to detect the lesion, if any. Next go for sputum examination for ziehl neelsen staining for tuberculosis, Gram s staining and culture and sensitvity. Meet your doctor with abovesaid reports. Ct scan of thorax may be required further to ease the diagnosis and treatment will be given as per the diagnosis. Meanwhile you may try cough suppressants, hemostatics like trenexamic acid, and absolute bed rest for few days... Best wishes