Common symptoms include, but are not necessarily limited to:

- Lack of facial control, (droopy eyelids)

- Double vision

- Headache or headache that gets better after vomiting

- Nausea and vomiting

- Weakness and fatigue

- Seizures

- Balance problems

- Numbness in face

Symptoms can develop slowly and subtly and may go unnoticed for months. In other cases, the symptoms may arise abruptly. A sudden onset of symptoms tends to occur with more rapidly growing, high-grade tumors.

Headaches as a result of raised intracranial pressure can be an early symptom of brain cancer. However, isolated headache without other symptoms is rarer, and other symptoms often occur before headaches become common. Certain warning signs for headache exist which make it more likely to be associated with brain cancer. These are as defined by the American Academy of Neurology: "abnormal neurological examination, headache worsened by Valsalva maneuver, headache causing awakening from sleep, new headache in the older population, progressively worsening headache, atypical headache features, or patients who do not fulfill the strict definition of migraine".

The brain is divided into 4 lobes and each lobe or area has its own function. A tumor in any of these lobes may affect the area's performance. The location of the tumor is often linked to the symptoms experienced but each person may experience something different.

- Frontal lobe tumors may contribute to poor reasoning, inappropriate social behavior, personality changes, poor planning, lower inhibition, and decreased production of speech (Broca's area).

- Temporal lobe: Tumors in this lobe may contribute to poor memory, loss of hearing, difficulty in language comprehension (Wernicke's area).

- Parietal lobe: Tumors here may result in poor interpretation of languages, decreased sense of touch and pain, and poor spatial and visual perception.

- Occipital lobe: Damage to this lobe may result in poor or loss of vision.

- Cerebellum: Tumors in this area may cause poor balance, muscle movement, and posture.

- Brain stem: Tumors on this can affect blood pressure, swallowing, and heartbeat.

The cause is still unknown. Researchers have not found any direct genetic link.

Symptoms of gliomas depend on which part of the central nervous system is affected. A brain glioma can cause headaches, vomiting, seizures, and cranial nerve disorders as a result of increased intracranial pressure. A glioma of the optic nerve can cause visual loss. Spinal cord gliomas can cause pain, weakness, or numbness in the extremities. Gliomas do not metastasize by the bloodstream, but they can spread via the cerebrospinal fluid and cause "drop metastases" to the spinal cord.

A child who has a subacute disorder of the central nervous system that produces cranial nerve abnormalities (especially of cranial nerve VII and the lower bulbar nerves), long-tract signs, unsteady gait secondary to spasticity, and some behavioral changes is most likely to have a pontine glioma.

Vision deficit usually occurs when lesions grow in the occipital lobe of the brain, causing a blurred daze for patients, especially in sensitivity to light. Focusing upon finer objects becomes a challenge, along with edge and border detection. Driving behind the wheel is dangerous when astroblastoma grows in residual tissue size, since peripheral vision can be insufficient. Horizontal nystagmus and other involuntary eye disorders can occur.

Along with cranial pressure, patients exhibit noticeable lethargy, increasing in severity as the tumor progresses. In the first few months, morning activities are usually unaffected; over time, these effects become more pronounced, especially late at night. Lethargy can disrupt vital signs, depleting energy and desire to perform simple cognitive tasks.

Gliomas can be classified according to whether they are above or below a membrane in the brain called the tentorium. The tentorium separates the cerebrum (above) from the cerebellum (below).

- The supratentorial is above the tentorium, in the cerebrum, and mostly found in adults (70%).

- The infratentorial is below the tentorium, in the cerebellum, and mostly found in children (70%).

- The pontine tumors are located in the pons of the brainstem. The brainstem has three parts (pons, midbrain, and medulla); the pons controls critical functions such as breathing, making surgery on these extremely dangerous.

In anywhere from fifty to eighty percent of cases, the first symptom of an oligodendroglioma is the onset of seizure activity. They occur mainly in the frontal lobe.

Headaches combined with increased intracranial pressure are also a common symptom of oligodendroglioma. Depending on the location of the tumor, any neurological deficit can be induced, from visual loss, motor weakness and cognitive decline. A computed tomography (CT) or magnetic resonance imaging (MRI) scan is necessary to characterize the anatomy of this tumor (size, location, heter/homogeneity). However, final diagnosis of this tumor, like most tumors, relies on histopathologic examination (biopsy examination).

There are many possible symptoms of oligodendrogliomas that are similar to other gliomas. These symptoms may include headache, seizure and speech or motor changes.

An MRI is better than a CT scan when a brainstem tumor is in the differential diagnosis.

Common symptoms include seizure, headaches, nausea and vomiting, memory loss, changes to personality, mood or concentration; and localized neurological problems.

The kind of symptoms produced depends more on the location of the tumor than on its pathological properties. The tumor can start producing symptoms quickly, but occasionally is an asymptomatic condition until it reaches an enormous size.

The symptoms of brain stem tumors vary greatly and can include ataxia, cranial nerve palsy, headaches, problems with speech and swallowing, hearing loss, weakness, hemiparesis, vision abnormalities, ptosis, and behavioral changes. Another possible symptom is vomiting. Headaches related to brainstem tumors may be worse shortly after waking up in the morning.

Oligodendrogliomas are a type of glioma that are believed to originate from the oligodendrocytes of the brain or from a glial precursor cell. They occur primarily in adults (9.4% of all primary brain and central nervous system tumors) but are also found in children (4% of all primary brain tumors). The average age at diagnosis is 35 years.

DIPG has a 5-year survival rate of <1%. The median overall survival of children diagnosed with DIPG is approximately 9 months. The 1- and 2-year survival rates are approximately 30% and less than 10%, respectively. These statistics make DIPG one of the most devastating pediatric cancers. Although 75–85% of patients show some improvement in their symptoms after radiation therapy, DIPGs almost always begin to grow again (called recurrence, relapse, or progression). Clinical trials have reported that the median time between radiation therapy and progression is 5–8.8 months. Patients whose tumors begin to grow again may be eligible for experimental treatment through clinical trials to try to slow or stop the growth of the tumor. However, clinical trials have not shown any significant benefit from experimental DIPG therapies so far.

DIPGs that progress usually grow quickly and affect important parts of the brain. The median time from tumor progression to death is usually very short, between 1 and 4.5 months. During this time, doctors focus on palliative care: controlling symptoms and making the patient as comfortable as possible.

Astrocytomas are a type of cancer of the brain. They originate in a particular kind of glial cells, star-shaped brain cells in the cerebrum called astrocytes. This type of tumor does not usually spread outside the brain and spinal cord and it does not usually affect other organs. Astrocytomas are the most common glioma and can occur in most parts of the brain and occasionally in the spinal cord. Within the astrocytomas, there are two broad classes recognized in literature, those with:

- Narrow zones of infiltration (mostly noninvasive tumors; e.g., pilocytic astrocytoma, subependymal giant cell astrocytoma, pleomorphic xanthoastrocytoma), that often are clearly outlined on diagnostic images

- Diffuse zones of infiltration (e.g., high-grade astrocytoma, anaplastic astrocytoma, glioblastoma), that share various features, including the ability to arise at any location in the CNS (Central Nervous System), but with a preference for the cerebral hemispheres; they occur usually in adults; and an intrinsic tendency to progress to more advanced grades.

People can develop astrocytomas at any age. The low-grade type is more often found in children or young adults, while the high-grade type are more prevalent in adults. Astrocytomas in the base of the brain are more common in young people and account for roughly 75% of neuroepithelial tumors.

Oligoastrocytomas are a subset of brain tumors that present with an appearance of mixed glial cell origin, astrocytoma and oligodendroglioma. These types of glial cells that become cancerous are involved with insulating and regulating the activity of neuron cells in the central nervous system. Often called a "mixed glioma", about 2.3% of all reported brain tumors are diagnosed as oligoastrocytoma. The median age of diagnosis is 42.5.

Oligoastrocytomas, like astrocytomas and oligodendrogliomas, can be divided into low-grade and anaplastic variant, the latter characterized by high , conspicuous cytologic , mitotic activity and, in some cases, microvascular proliferation and necrosis.

However, lower grades can have less aggressive biology.

These are largely supratentorial tumors of adulthood that favor the frontal and temporal lobes.

Glioblastoma, also known as glioblastoma multiforme (GBM), is the most aggressive cancer that begins within the brain. Initially, signs and symptoms of glioblastoma are non-specific. They may include headaches, personality changes, nausea, and symptoms similar to those of a stroke. Worsening of symptoms often is rapid. This may progress to unconsciousness.

The cause of most cases is unclear. Uncommon risk factors include genetic disorders such as neurofibromatosis and Li–Fraumeni syndrome, and previous radiation therapy. Glioblastomas represent 15% of brain tumors. They can either start from normal brain cells or develop from an existing low-grade astrocytoma. The diagnosis typically is made by a combination of CT scan, MRI scan, and tissue biopsy.

There is no clear way to prevent the disease. Typically, treatment involves surgery, after which chemotherapy and radiation therapy are used. The medication temozolomide is used frequently as part of chemotherapy. High dose steroids may be used to help reduce swelling and decrease symptoms. It is unclear whether trying to remove all or simply most of the cancer is better.

Despite maximum treatment, the cancer usually recurs. The most common length of survival following diagnosis is 12 to 15 months, with fewer than 3% to 5% of people surviving longer than five years. Without treatment, survival is typically three months. It is the most common cancer that begins within the brain and the second most common brain tumor, after meningioma. About 3 per 100,000 people develop the disease a year. It most often begins around 64 years of age and occurs more commonly in males than females. Immunotherapy is being studied in glioblastoma with promising results.

A diffuse intrinsic pontine glioma (DIPG) is a tumour located in the pons (middle) of the brain stem. The brain stem is the bottommost portion of the brain, connecting the cerebrum with the spinal cord. The majority of brain stem tumours occur in the pons and are diffusely infiltrating (they grow amidst the nerves), and therefore cannot be surgically removed. Glioma is a general name for any tumour that arises from the supportive tissue called glia, which help keep the neurons in place and functioning well. The brain stem contains all of the afferent (incoming) neurons within the spinal cord, as well as important structures involved in eye movements and in face and throat muscle control and sensation.

Ganglioglioma is a rare, slow-growing primary central nervous system (CNS) tumor which most frequently occurs in the temporal lobes of children and young adults.

Gliosarcoma is a rare type of glioma, a cancer of the brain that comes from glial, or supportive, brain cells, as opposed to the neural brain cells. Gliosarcoma is a malignant cancer, and is defined as a glioblastoma consisting of gliomatous and sarcomatous components.

It is estimated that approximately 2.1% of all glioblastomas are gliosarcomas. Although most gliomas rarely show metastases outside the cerebrum, gliosarcomas have a propensity to do so, most commonly spreading through the blood to the lungs, and also liver and lymph nodes.

Gliosarcomas have an epidemiology similar to that of glioblastomas, with the average age of onset being 54 years, and males being affected twice as often as females. They are most commonly present in the temporal lobe.

Review of past cases, patients often do not exhibit many symptoms or obtain a diagnosis until they are around 20 to 40 years old. If the patient does show symptoms, it is most likely due to pressure from growth of the tumor. Depending on which part the epidermoid is pressing against can result in varying symptoms.

- Headaches – often worse in the morning or by changing positions; can be constant and become more severe or more frequent; not your typical headache

- Vision problems like blurred vision, double vision, or loss of peripheral vision

- Loss of sensation or movement in the arms, legs, or face

- Dizziness or difficulty with balance and walking, unsteadiness, vertigo

- Speech difficulties

- Confusion in everyday matters or disorientation

- Seizures, especially in someone who hasn’t had seizures before

- Hearing loss or buzzing or ringing in the ear

- Swallowing or speech difficulty

- Fatigue or sleepiness especially in children

Gangliogliomas are generally benign WHO grade I tumors; the presence of anaplastic changes in the glial component is considered to represent WHO grade III (anaplastic ganglioglioma). Criteria for WHO grade II have been suggested, but are not established. Malignant transformation of spinal ganglioglioma has been seen in only a select few cases. Poor prognostic factors for adults with gangliogliomas include older age at diagnosis, male sex, and malignant histologic features.

A nervous system neoplasm is a tumor affecting the nervous system. Types include:

- Nerve sheath tumor

- Brain tumor

- Arachnoid cyst

- Optic nerve glioma

Astrocytoma causes regional effects by compression, invasion, and destruction of brain parenchyma, arterial and venous hypoxia, competition for nutrients, release of metabolic end products (e.g., free radicals, altered electrolytes, neurotransmitters), and release and recruitment of cellular mediators (e.g., cytokines) that disrupt normal parenchymal function. Secondary clinical sequelae may be caused by elevated intracranial pressure (ICP) attributable to direct mass effect, increased blood volume, or increased cerebrospinal fluid (CSF) volume.