When a tumour is removed from the brain, what happens to the space the tumour occupied? Does the brain matter grow back or is there a cavity?

It's important to remember that correlation does not imply causation. Just because you have pain on the right side of your brain does not mean you have a brain tumor. There are many other potential causes of pain on the right side of your head, such as a sinus infection or a toothache.

That being said, it is still important to get checked out by a doctor if you are experiencing any unusual symptoms. A brain tumor can be a very serious condition, and early diagnosis and treatment is essential for the best possible outcome. So if you are concerned, don't hesitate to see a doctor.