The first step in diagnosing brain cancer involves evaluating symptoms and taking a medical history. If there is any indication that there may be a brain tumor, various tests are done to confirm the diagnosis.

 The diagnosis is done by either a neurologist (a specialist in brain and nerve disorders) or an oncologist (a doctor who specializes in cancer treatment)who both check for physical signs

 Nervous system examination: The doctors check the nerves or the brain which control the eyes and face, check for equal strength and sensation on both sides of the body, coordination and balance, and memory and judgment.

 Mental exercises, such as simple arithmetic and simple questions.

 An eye examination using an ophthalmoscope (instrument which shines a light at the back of the eye). This test is done to see if the optic disc at the back of the eye is swollen. A swollen optic disc is known as papilloedema and is a sign of raised intracranial pressure due to the growing brain tumor.

 Hearing tests.

 Facial muscle tests - smiling, grimacing.

 Tongue movement is also tested.

Checking the strength of your arms and legs, knee jerks and other reflexes.

The doctor will test one's ability to feel sensations likepinpricks on areas of skin, to tell the difference between hot and cold and possibly to recognize the feeling and shape of familiar objects like coins.

Gait of the patient is noted.

Routine laboratory tests may be performed such as analysis of blood, electrolytes, liver function tests, and a blood coagulation profile. Blood or urine tests may be done to detect drug use.

CT scan: An X-ray machine linked to a computer takes a series of detailed pictures of the head. The patient may receive an injection of a special dye so the brain shows up clearly in the pictures. The pictures can show tumors in the brain.

MRI: A powerful magnet linked to a computer makes detailed pictures of areas inside the body. These pictures are viewed on a monitor and can also be printed. Sometimes a special dye is injected to help show differences in the tissues of the brain. The pictures can show a tumor or other problem in the brain.

Positron emission tomography (PET scan): It helps the physician evaluate brain function and cell growth by producing images of physical and chemical changes in the brain. PET can precisely locate a tumor and detect metastatic and recurrent brain cancer at earlier stages than MRI or CT scan. This technique also can be used to evaluate the tumor's response to chemotherapy and radiation treatment.

Angiogram: Dye injected into the bloodstream flows into the blood vessels in the brain to make them show up on an x-ray. If a tumor is present, the doctor may be able to see it on the x-ray.

Skull x-ray: Some types of brain tumors cause calcium deposits in the brain or changes in the bones of the skull. With an x-ray, the doctor can check for these changes.

Spinal tap: The doctor may remove a sample of cerebrospinal fluid with local anesthesia. The doctor uses a long, thin needle to remove fluid from the spinal column. A laboratory checks the fluid for cancer cells or other signs of problems.

Myelogram: This is an x-ray of the spine. A spinal tap is performed to inject a special dye into the cerebrospinal fluid. The patient is tilted to allow the dye to mix with the fluid. This test helps the doctor detect a tumor in the spinal cord.

Biopsy: The removal of tissue to look for tumor cells is called a biopsy. A pathologist looks at the cells under a microscope to check for abnormal cells. A biopsy is the only sure way to diagnose a brain tumor. the three ways of obtaining the tissue samples are:

Needle biopsy: The surgeon makes a small incision in the scalp and drills a small hole into the skull. This is called a burr hole. The doctor passes a needle through the burr hole and removes a sample of tissue from the brain tumor.

Stereotactic biopsy: An imaging device, such as CT or MRI, guides the needle through the burr hole to the location of the tumor. The surgeon withdraws a sample of tissue with the needle.

Biopsy at the same time as treatment: The surgeon takes a tissue sample when the patient has surgery to remove the tumor.