Medical science may not really yet understand the causes of brain tumors; scientists may not understand what relly brings this horrific disease on. What they do know is how the process gets started.
A brain tumor starts with cells that have certain specific kinds of genetic flaws. When these cells with flawed DNA multiply, they propagate those flaws that they have too. These cells usually outlast healthy, regular cells. What that means is that pretty soon, there's more of them than regular cells. And then you have a tumor.
You've probably heard a lot about how if you have an excessive cell phone habit, that it may result in a brain tumor. Now no one has actually proven anything like this. While doctors know very little about the causes of brain tumors that they can actually prove, they have some pretty good ideas of where to look for those causes.
Since they can't really prove any of it yet, they like to call them risk factors. Yes, your cell phone is one of them. The more your brain is exposed to something called "ionizing radiation", the more you are at risk of developing a tumor in the brain.
What is ionizing radiation anyway? In concept, it's pretty simple. An ion is an atom that's been stripped of its electrons. Certain kinds of radiation manage to do this to the atoms they come across. That's the kind of radiation you're talking about here. Radiation from your microwave and your cell phones are capable of doing this.
A few find it hard to believe that something as innocent looking as a cell phone or microwave might be capable of anything like this. Well then, try to call to mind what else does ionizing radiation. Nuclear power plants would be one example.
Some people find themselves at higher risk of brain tumors through the kind of environment they of work in. Certain kinds of factory jobs are known to expose workers to harmful chemicals that may cause tumors. For instance, if you happen to work in an oil refinery or a factory that manufactures PVC, those are considered reasonable causes of brain tumors.
Soldiers happen to be particularly at risk, too. Iraq war veterans, for instance, come by more brain tumors than most other populations. Apparently, the nerve gas that they were exposed to, did this to them. Head injuries are known to cause it, too something that soldiers often have to risk facing.