Brain Tumors Side Effects

The location and size of a brain tumor are major factors in determining how it affects the body. Brain tumor symptoms and side effects depend on which part of the brain tissue is being damaged or compressed by the uncontrolled growth of cells.

Tumor Biology

Understanding tumor biology can help patients learn about the various side effects they experience. A tumor is composed of cells that grow and reproduce out of control. Unlike other parts of the body, the skull does not allow extra space for this increase in mass. The resulting pressure, therefore, can wreak havoc on the surrounding tissue. Because different parts of the brain are responsible for different functions, the location and symptoms of the tumor are related.

Brain tumors cause a “mass effect,” or damage to brain tissue due to increased intracranial pressure (IICP). IICP can result from:

  • Edema: Swelling of the brain from fluid accumulation
  • Hydrocephalus: Blockage of CSF fluid flowing in the brain
  • Size: Growing mass of cells in the tight confines of the skull.

Some common brain tumor symptoms—such as headaches, seizures, and nausea—are associated with most types of brain tumors. Other symptoms, called “focal” or “localized” symptoms, are more specific to the area of the brain affected.

Brain Stem Tumor Symptoms

The brain stem controls motor and sensory nerves, the heart, breathing and reflexes. Tumors in this section of the brain may cause:

  • One-sided facial weakness
  • Speaking difficulty
  • Swallowing difficulty
  • Uncoordinated walk
  • Vomiting just after awakening.

Frontal Lobe Side Effects

The frontal lobe controls behavior and emotion, problem solving, judgment and coordinated movement. Symptoms arising from tumors in the frontal lobe may include:

  • Impaired judgment
  • Loss of sense of smell
  • One-sided paralysis
  • Personality changes
  • Seizures
  • Short-term memory loss.

Occipital Lobe Symptoms

The occipital lobe is associated with understanding visual images and determining the meaning of the written word. Brain tumor side effects in this lobe include:

  • Blindness in one direction
  • Seizures
  • Visual disturbances.

Parietal Lobe Side Effects

The parietal lobe controls responses to internal stimuli, reading and some visual functions. Common brain tumor symptoms in the parietal lobe are:

  • Language disturbances
  • Loss of reading ability
  • Loss of writing ability
  • Seizures
  • Spatial disorders.

Pituitary Gland Symptoms

The pituitary gland is responsible for hormone secretion. A tumor in this region may cause side effects such as:

  • Breast enlargement
  • Headaches
  • Vision changes.

Temporal Lobe Side Effects

The temporal lobe controls hearing, depth perception and understanding of spoken words. Temporal lobe brain tumors are often “silent,” or without symptoms, but side effects may include:

  • Impaired vision
  • Inability to recognize sounds
  • Seizures.

Metastatic Brain Tumor Side Effects

Due to the biology of cancer cells, metastatic brain tumors tend to cause swelling (edema) in the brain. Specific symptoms depend on the tumor location, but this swelling commonly leads to symptoms such as:

  • Headache
  • Nausea
  • Vomiting.


National Brain Tumor Society Staff. (n.d.). Brain tumor. Retrieved April 19, 2010, from the National Brain Tumor Society website:

American Brain Tumor Association Staff. (n.d.). Symptoms. Retrieved April 27, 2010, from the American Brain Tumor Association website:

American Brain Tumor Association Staff. (n.d.). A primer of brain tumors. Retrieved April 27, 2010, from the Harvard Medical School website: