My dad is having black mucus twice a day. With no coughing, no chest congestion, no pain, no stools discoloration or darker shades of any other bodily excretions. Not even nose. It's only the cough from throat having black fluid. Almost 20-25 % of the mucus is such black in colour. He was a chronic smoker 3-4 years ago. But now he's quit it. He had a heart attack with left sided hemiparesis on 8th may, 2021 and got discharged on 24th aug, 2021. With doctors saying he does not have major copd issues. He is on the mentioned medications.