Coughing up sputum in the morning appears brown or black, may be related to bleeding gums, may also be caused by respiratory diseases. 1. Bleeding gums. When there are blood system diseases, long-term use of anticoagulant drugs, or chronic periodontitis, gums may bleed at night, swallowed in the digestive tract during sleep, coughing up sputum in the morning may cough up partially dried black and brown bloody sputum. 2. Respiratory diseases. Coughing up sputum in the morning is brown, black may also be caused by respiratory diseases, respiratory tract inflammation abnormal secretion can also appear black and brown sputum. Coughing up sputum in black and brown, it is recommended to go to the hospital to find out whether it is caused by digestive or respiratory diseases, and find out the cause of the disease in a timely manner.