Symptoms of late interstitial pneumonia include the following: 1. irritating dry cough with little sputum; 2. exertional dyspnea, which improves at rest and worsens with movement; 3. malnutrition, emaciation, and poor health; 4. cyanosis of the lips, cyanosis of the fingers, and large mouth breathing; 5. involvement of the heart and digestive system; 6. complications, most commonly infections, especially of the respiratory tract. In addition to coughing and dyspnea, coughing sputum will also occur, and the color, nature and amount of sputum will be different depending on the different pathogens.