Swelling is a serious complication of brain injury and can lead to brain damage. But there are other causes of brain swelling as well, so it’s important to know symptoms.

Actress Kate Walsh revealed that she was diagnosed with a brain tumor in 2015 - read about the symptoms that raised a red flag.

Approximately 180,000 people are diagnosed with a brain tumor each year, according to the American Brain Tumor Association. A brain tumor is simply a mass of abnormal cells that grows in the brain. The temporal lobe processes sounds and spoken words as well as memory and emotion.

Brain cysts are spheres that are filled with fluid almost like fluid-filled balloons in the brain. The fluid may contain blood, tissue, or minerals.

Healthy people possess levels of brain chemicals that lie within a certain normal range. When internal or external factors either deplete the brain of these chemicals or stimulate it to produce excess amounts, a chemical imbalance occurs.

Brain swelling, known in medical terminology as cerebral edema, is a manifestation of various brain injuries such as cancer or trauma, and is dangerous because it raises the pressure inside the skull. The skull is a thick chamber that is not compliant, which means it does not stretch.

The cerebellum is located in the posterior fossa along with the fourth ventricle and brain stem. Approximately 15 to 20 percent of tumors arise in the posterior fossa, according to New York Presbyterian Hospital.

Brain tumors that begin in the brain are called primary brain tumors, and they may or may not be cancerous. Other brain tumors arise when cancer from another location in the body spreads, or metastasizes, to the brain. These metastatic brain tumors are 4 to 5 times more common than primary brain tumors.

The brain contains three main parts: the forebrain, the midbrain and the hindbrain. The cerebrum is the largest part of the brain. Located in the forebrain, it is divided into the frontal lobe, parietal lobe, occipital lobe and temporal lobe.

The brain consists of four lobes: the frontal, temporal, occipital and parietal. Imagining a line on the top of the head from ear to ear, the portion of the brain at the top of the skull just to the rear of the line is the parietal lobe.

Headache is the most common symptom of brain tumors. Although the brain itself feels no pain, other structures including blood vessels, the covering of the brain, and nerves in the head produce pain in response to pressure or displacement caused by a tumor.

A brain hemorrhage, or hemorrhagic stroke, occurs when a blood vessel inside the brain bursts, causing bleeding into brain tissues. It is a life-threatening medical emergency; quick treatment can slow or stop the bleeding, minimizing damage.