<s>[INST] My dad is 93 years old. He had a cold for a week. My brother took him to the doctors yesterday. They told him he has fluid in one of his lungs and they were going to drain it. This was 24 hours ago. Are they purposely not doing it because of his age? He is usually very healthy. [/INST] Hello and Welcome to ‘Ask A Doctor’ service.I have reviewed your query and here is my advice.Fluid in the lung is mostly because of 1. Heart problems 2. Pneumonia or infection 3. Low protein Maybe they are waiting for spontaneous resolution of fluids. Go and ask for it. Hope I have answered your query. Let me know if I can assist you further.Regards,      Dr. Chandra Shekhar </s>