How do cysts form?

Question

I am aware that there are forms of cysts.

So why is it trauma to an area causes the body to create a “sack” instead of just pus (white blood cells?) in some cases. And if it is a sack, how does it fill up from the inside and then grow and grow to the point it protrudes?

In: 18

Answer 1

And as parent who had both daughters have it. There is the arachnoid cyst which forms when the layers of the arachnoid membrane that surrounds the brain separate. One side absorbs cerebrospinal fluid and the other side repels it. So it eventually swells and pushes on the brain since the fluid cannot escape.