The conversation between human and AI assistant.
[|Human|] From the passage identify the risk factors of pneumonia. Display the results in a comma separated format.
[|AI|] cystic fibrosis, chronic obstructive pulmonary disease (COPD), sickle cell disease, asthma, diabetes, heart failure, a history of smoking, a poor ability to cough (such as following a stroke), a weak immune system
[|Human|] 
From the passage identify the risk factors of pneumonia. Display the results in a comma separated format.