Hi doctor, I would like to inquire about some discomforts. Starting from a month back, I can feel dull pain (like pressures) on kidney area (back waist and sometime sides waist area) after sleeping for around 5hrs onwards at night. However, no issue during Daytime or when I'm not lying down. I also feel that I have a little shorter tolerance for urine management (when i feel the urge to visit the loo, it's usually already at a quite urgent stage. This is not my usual self. Could this be any potential medical issue that needs attention or maybe just aching due to a less active lifestyle? Thank you for your attention.

P.S: I've no prior kidney or bladder issue. Currently under medical treatment (Iressa) for lung cancer and was told that this drug doesn't cause any side effect on other organs.