Hello, what is your age and general health?
How long have you had this problem?
How long have you had the cough?
Any phlegm? What color?
Do you take any medication?
When did he have the hip surgery?
Is he short of breath?
Any swelling of ankles or legs?
He had his surgery on the 16th of November
No he seems to be breathing fine. Not sure about swelling.
There are several things that need to be excluded and owing to his age then he needs to see a doctor today.
One strong possibility is a chest infection or pneumonia, this can happen after people have had general anesthetics and have been in hospital. He needs a doctor to listen to his chest, examine any sputum and consider a chest x-ray.
Another possible cause is a clot in the lung, this tends to cause pain regardless of breathing in/out but after an operation on the lower limbs is a high risk possibility and would require some blood tests and scans to rule this out. Usually people are given injections in hospital to reduce the risk but it still needs to be ruled out.
Other possible cause of pain when breathing in/out is a fractured rib and this can occur when elderly people fall, or it may simply be inflamed muscles of the chest wall.
As you can see there are several possibilities and we do not have enough information to suggest which is most likely and this means he must have an evaluation by a doctor in person today.