The common clinical causes of dark brown sputum in the morning include environmental factors and disease factors.
1. Environmental factors: for people who often smoke or work and live in a smoky environment, the harmful substances in tobacco and heavily polluted air will cause irritation to the respiratory mucosa, thus causing damage to the respiratory mucosa and inflammatory reaction, when the mucosal capillaries rupture and bleed, it will lead to coughing up brown sputum in the morning.
2. Disease factors: when the body suffers from tuberculosis, pneumonia and other infectious diseases of the lungs, as well as lung cancer and other diseases, it is easy to cause the local bronchial mucosa capillary rupture, bleeding and other situations, and thus may cough up dark brown sputum after waking up in the morning.
It is recommended that people with this condition should consult a doctor for further imaging tests of the lungs in order to make a clear diagnosis.