Risk factors do not necessarily cause a disease. One might also be exposed to these factors and not get sick.
Age. Children younger than five years and adults older than 60 years are at higher chances of contracting meningitis. The risk of Alzheimer disease will also increase with age. In fact, at the age of 85, there are fifty percent chances of one developing the Alzheimer disease.
Family history. People with family histories of brain cancer will have higher chances of the cancer. Those with parents or siblings with the Alzheimer disease are also at greater risk of developing it. The more the family members are with the condition, the higher the chances of getting it. Other brain diseases include aneurysms.
A weakened immune system. This can be as a result of previous infections such as HIV / AIDS. This HIV can cause deficiency of the immune system. A person with an impaired immune system will be at a higher risk of conditions such as lymphomas of the brain. Immuno suppression will also make one susceptible to other brain diseases such as bacterial meningitis.
Overcrowding. Viral meningitis easily spreads via direct contact with infected respiratory secretions. Therefore in an overcrowded place of residence, the brain disease is likely to spread because of improper hygiene such as failure to cover ones mouth when coughing and poor disposal of used tissue.
Continued contact with patients with meningitis. Meningococcal meningitis is one of the brain diseases that can be transmitted by a patient to their caretaker. One can be at risk whether or not they have been put under prophylaxis, antibiotics to prevent them from the disease.
Continued exposure to radio active material or chemicals such in industries will increase the risk of brain cancer.
Excessive consumption of alcohol will increase the chances of Alzheimer disease and brain aneurysms.
Sex. More women than men get brain aneurysms and Alzheimer's disease.
The herpes viruses can cause viral meningitis. Cystic fibrosis, diabetes mellitus and sickle cell diseases will also increase risks of meningitis.
Cardiovascular diseases will make one at higher risk of vascular dementia and Alzheimer disease. The chances of Alzheimer disease will also be increased by having diabetes.
Polycystic kidney disease will increase the chances of brain aneurysms.
Other risk factors of brain diseases include stress, depression, drug abuse, failure to exercise the brain, head injuries, smoking and brain defects such as dural defects.