Unfortunately, brain cancer causes and risk factors are often poorly understood. Brain cancer isn't contagious, so you can't catch it from another person. However, there are a few things that make it more likely for you to develop it.

Understanding Brain Cancer Causes and Risk Factors:

Brain cancer is a rare type of cancer. It is very rare for people to develop tumors on the brain, and of those, only 50% are malignant. Men are more likely to have a malignant tumor, whereas benign tumors and unknown diagnosis tumors are more common in women.

Known Brain Cancer Causes and Risk Factors:

All cancers are caused by genetic mutations in someone's DNA. Why this happens, however, is poorly understood. That said, there are some known risk factors associated with brain cancer. These include:

1. Age, with brain tumors being more common in younger adults. They are also the second most common cancer type in children under 15, and the fourth most common in those aged between 15 and 24.

2. Medical radiation, which is the only risk factor that is known to be definite. Meningiomas and malignant gliomas occur more frequently in people who have had head x-rays, CT scans, or radiotherapy. This does not mean, however, that everybody who undergone those will develop brain cancer.

3. Previous cancers, particularly if people had cancer as a child. Adults who had non-Hodgkin lymphoma or leukemia are also at an increased risk. Some evidence suggests that all previous cancers may increase the chance of developing a brain tumor. This may be due to patients receiving radiotherapy, and methotrexate for leukemia.

4. Family history and genetics, particularly with regards to rare genetic conditions such as Gorlin, Turcot, Turner, Von Hippel-Lindau, and Li-Fraumeni syndrome, tuberous sclerosis, and type 1 and 2 neurofibromatosis. If a direct sibling is diagnosed with a brain tumor, you also have an increased chance.

5. Medical conditions and medications, particularly if people have HIV or AIDS, where the chance of developing a brain tumor is twice as large. Women who take HRT after menopause also have a slight increase in their risk. Some evidence suggests that taking oral contraceptives increases the chance as well.

6. Body type and exercise, with people who are overweight having a slightly increased chance of developing meningioma (but not glioma). Children who weigh at least 4 kg at birth also have an increased risk. There is no known link between diet and brain tumors, but those who are physically active may have a reduced risk.

7. Other factors are being researched. There is a suggestion that living near power lines increases the chance of developing a brain tumor, but this has not been proven yet. Similarly, there is no evidence to suggest using mobile phones increases the chance of brain cancer. Hair dye also has not been proven to be a risk. Smoking may increase the chance, but no evidence exists to show an increased risk due to alcohol.

Reducing the Risk of Brain Cancer:

Some evidence suggests that those who have allergies are at a lower risk of developing brain cancer. Some trials also showed a decreased risk in those who took anti-inflammatory drugs and aspirin.