Brain is the organ that is essential as well as heart. It is not live when a person’s brain cannot function and the rest of the body can. Without brain all the other parts are unable to function as well anyway. There are however dramatic conditions when a person’s brain actually fails to work and one of them is brain cancer. It is a very serious condition and actually lethal. Before talking about brain cancer causes it should be explained what brain cancer actually is. In fact, it is a tumor which is malignant caused by the abnormal cells growth. Due to some reasons cells start to divide uncontrollably and not in the way they are supposed to. The process usually takes place in the following areas – brain, pineal or in cranial nerves. It is also possible that the very cells that participate in actual brain formation are brain cancer cause in some cases. It is most of the time that brain tumor is malignant. There are different brain cancer causes. One of them is the effect of radiation. It is generally the most frequent one. The development of brain tumor is often observed in people who work in the industry and some places where nuclear energy is anyhow involved. Among all the spheres this working sector is considered the riskiest and most dangerous in this respect. It is nowadays well-known even to a school kid how extremely dangerous nuclear radiation is. It is generally harmful for an organism and for brain in particular. In the list of other brain cancer causes is genetics (and also heredity). It is actually not the last and if in the family history there were relatives who had the condition, it has some percent of appearance probability. Genetic mutation that is expressed in the absence of some suppressing genes responsible for keeping the tumor genes at bay can lead to brain cancer as well. Cancer in some other part of the body can also be among brain cancer causes. Such brain tumors are called secondary and they are no less dangerous. In fact the cases of secondary breast cancer are more severe than just brain cancer as it is. Cancer of lungs and colon as well as breast cancer and melanoma or sarcoma are able to evoke secondary brain tumor. Brain tumor can be cancerous or not but still if the cells of a tumor are malignant, they always indicate cancer. That is why tumors are in the list of brain cancer causes. There was written about secondary cancer that is the result of some other cancer; while primary brain cancer happens in the result of the healthy cells’ mutation. The statistics shows that the cases of primary brain cancer are not so frequent as the secondary one. Different factors of environment are also in the list of brain cancer causes. For example, Vinyl Chloride exposure is extremely dangerous. This is a compound of some plastic materials. Smoking, HIV/Aids infection as well as chemical exposure (i.e. formaldehyde and Acrylonitrile) are among brain cancer causes together with such factors as age and race and even sex. It has been concluded that brain cancer happens more frequently in men. Brain cancer causes are numerous; however, the condition is still under the investigation and the process and the reasons are still studied. It helps to treat and prevent the condition.