My father has been suffering from severe cough since last few days. As a result, he has not been able to sleep properly at night. Due to cough, he couldn't sleep for two nights at a stretch. Now for the last few days, he seems to be hallucinating. Once he wakes up after sleeping for a short stretch during the day, he says imaginary  things. And then he is back to normal. He is slowly recovering from the cough problem but still he is not able to sleep properly at night.