Brain cancer is a disease of the brain where cancer cells (malignant) grow in the brain tissue. Cancer cells grow to form a mass of cancer tissue (tumor) that interferes with brain tissue functions such as muscle control, sensation, memory, and other normal body functions. Tumors composed of cancer cells are called malignant tumors, and those composed of noncancerous cells are called benign tumors. Cancer cells that develop from brain tissue are called primary brain tumors. Statistics suggest that brain cancer is not rare and is likely to develop in about 20,000 people per year.

There are two main types of brain cancer. Primary brain cancer starts in the brain. Metastatic brain cancer starts somewhere else in the body and moves to the brain. Brain tumors can be benign, with no cancer cells, or malignant, with cancer cells that grow quickly.

Primary brain cancer rarely spreads beyond the central nervous system, and death results from uncontrolled tumor growth within the limited space of the skull. Metastatic brain cancer indicates advanced disease and has a poor prognosis.
Metastatic brain tumors are made of cancerous cells from a tumor elsewhere in the body. The cells spread to the brain from another tumor in a process called metastasis. About 25% of tumors elsewhere in the body metastasize to the brain.

Symptoms of Brain Cancer

Brain tumors can damage vital neurological pathways and invade and compress brain tissue. Symptoms usually develop over time and their characteristics depend on the location and size of the tumor.
Cancers are typically painless at first. As they grow, the first symptom is often a mild discomfort, which may steadily worsen into increasingly severe pain as the cancer enlarges. The pain may result from the cancer compressing or eroding into nerves or other structures.

The symptoms are caused by the tumor pressing on or encroaching on other parts of your brain and keeping them from functioning normally.
A sign is also an indication that something is not right in the body. But signs are defined as things that can be seen by a doctor, nurse, or other health care professional. Fever, rapid breathing rate, and abnormal breathing sounds heard through a stethoscope may be signs of pneumonia.

As the skull is made of bone, there is a fixed amount of space for the brain to take up. The growing tumour increases the pressure inside this fixed space. This is called 'raised intracranial pressure'.

Motion sickness is a very common disturbance of the inner ear that is caused by repeated motion such as from the swell of the sea, the movement of a car, the motion of a plane in turbulent air, etc. In the inner ear (which is also called the labyrinth), motion sickness affects the sense of balance and equilibrium and, hence, the sense of spatial orientation.

Brain tumors can often present different symptoms depending on the location of the tumor. There are general brain tumor symptoms that need to be checked out by a doctor if they are experienced.

Fits are one of the commonest symptoms of brain tumours. About 1 in 4 people with a brain tumour first go to their doctor because they have had a fit. A fit can just be jerking or twitching of a hand, arm or leg.

At the late stages of the disorder, dramatic changes in blood pressure may occur. Seizures are a common symptom of benign brain tumors and slow-growing cancers. Tumors can cause a part of the body to weaken or feel paralyzed. Hearing, sight and the sense of smell can be affected.