Signs and Symptoms
Brain cancer can affect how you think, feel, and function, often in initially subtle ways. Recognising early signs and knowing when to seek help can make a critical difference.
How Tumours Affect the Brain
Brain cancer symptoms develop when a tumour disrupts normal brain function, either by growing into brain tissue, pressing on nearby structures, or increasing pressure within the skull.
As the tumour grows, it can displace healthy brain tissue and cause swelling (oedema) in the surrounding brain.
Tumours may also block the normal flow of cerebrospinal fluid, leading to increased pressure in the brain (hydrocephalus). These changes can affect how different parts of the brain function, leading to a wide range of symptoms depending on the tumour’s location.
Understanding how and why these symptoms occur can help you recognise changes early and seek appropriate medical care.
Why Symptoms Differ and Overlap
Brain tumours can cause a wide range of symptoms that vary depending on the tumour’s location, size, growth rate, and the amount of pressure or swelling it causes in the brain.
However, many symptoms are shared across different tumour types because they are driven by increased pressure in the skull or disruption of normal brain function. These symptoms can occur in both primary brain tumours and secondary (metastatic) tumours that have spread from other parts of the body.
Common Clinical Presentations
Headaches related to brain tumours are often worse in the morning or when lying down and may become persistent over time. Headaches may also be accompanied by nausea and vomiting, particularly when pressure inside the skull is increased.
Patients may also experience seizures, which can include unusual sensations such as strange smells, muscle jerking, tingling or numbness, or behavioural changes that were not present before. Seizures are more common in tumours that affect the outer parts of the brain (cerebral cortex).
The Role of Tumour Location
Although some symptoms are common, the type and severity of symptoms can vary depending on the tumour’s location, growth rate, and the amount of pressure or swelling it causes in the brain.
These patterns are seen in both primary brain tumours and secondary (metastatic) tumours. As different parts of the brain control different functions, a tumour may interfere with the specific functions of the region in which it develops.
Tumours that arise in certain areas therefore tend to cause symptoms linked to specific functions controlled by that region.
Some symptoms may be subtle at first and become more noticeable as the tumour grows or pressure in the brain increases.
Because it is difficult to predict who will develop seizures, anti-seizure medicines are usually started after a seizure occurs.
In some cases, they may be used around the time of surgery.
This highlights the importance of recognising symptoms early and seeking medical assessment. Children and young adults may present with different symptoms compared with adults.
For example, tumours in the posterior fossa, which are more common in children, can block the flow of cerebrospinal fluid and increase pressure in the brain, leading to symptoms such as vomiting and headaches.
Symptoms can also result from treatment, as therapies may affect brain function and lead to short-term or long-term side effects. In children, the developing brain is more vulnerable to treatment effects, which can impact learning, memory, growth, and hormone function. Treatments aim to target the tumour while minimising damage to healthy brain tissue.
Age-Specific Symptoms and Treatment Effects
Children and young adults may present with different symptoms compared with adults. For example, tumours in the posterior fossa, which are more common in children, can block the flow of cerebrospinal fluid and increase pressure in the brain, leading to symptoms such as vomiting and headaches.
Symptoms can also result from treatment, as therapies may affect brain function and lead to short-term or long-term side effects. In children, the developing brain is more vulnerable to treatment effects, which can impact learning, memory, growth, and hormone function. Treatments aim to target the tumour while minimising damage to healthy brain tissue.
Early Signs of a Brain Tumour
Some early signs of a brain tumour depend on whether symptoms are focal or generalised. Focal symptoms relate to the specific area of the brain where the tumour is growing. Generalised symptoms occur as the tumour increases in size and increases pressure within the skull, affecting brain functions more broadly.
Frequent headaches, especially when accompanied by nausea and vomiting, are often linked to increased pressure inside the skull. Brain imaging is often recommended after a first seizure to help rule out underlying causes, including a brain tumour. Patients and carers may also notice subtle personality or behavioural changes in the early stages.
Overall, early symptoms are often not specific to the tumour type but instead reflect the area of the brain affected. Other common early signs may include disturbed sleep, memory difficulties, changes in mood and increased drowsiness.
It is important to recognise that early symptoms may present differently in children compared with adults. For instance, in younger children, symptoms such as headaches may be difficult to recognise or describe, which can delay diagnosis. In adolescents, when tumours affect hormone-controlling areas of the brain, delayed or stunted growth and puberty may also be seen. Despite these differences, many early symptoms are shared across age groups, including recurrent headaches, nausea, vomiting, seizures, and behavioural changes.
Common Brain Tumour Symptoms
Brain tumours differ between children and adults in how often they occur, their histology, molecular features, location within the brain, and outcomes. Children may also have difficulty describing their symptoms, which can delay recognition of those symptoms and a formal diagnosis.
Headache
May occur more often in the morning, may disrupt sleep
Note: May be related to raised intracranial pressure, and often occurs with other symptoms
Vomiting
Early-morning vomiting common
Note: Vomiting with headache can suggest raised intracranial pressure
Seizures
May appear at diagnosis or as tumour grows
Note: Preventive anti-seizure medicine is not routinely recommended if you have never had a seizure; seizures are more common in tumours above the tentorium (supratentorial)
Balance / Walking Problems
Trouble walking or poor coordination
Note: More frequent with tumours below the tentorium (infratentorial)
Vision Changes
May not always be noticed
Note: Vision changes depend on tumour location and raised intracranial pressure
Behaviour / Personality Changes
Irritability, mood changes, confusion
Note: Early subtle changes may be missed, especially in children
Hormone-related symptoms
May result in delayed or arrested puberty, or slowed growth
Note: Can occur when tumours affect the hypothalamus or pituitary gland
Other Focal Symptoms
Weakness, numbness, facial drooping
Note: Symptoms mainly reflect tumour location, while tumour grade influences how quickly symptoms develop or worsen
Headache
May occur, sometimes worse in the morning or with changes in position
Note: May be related to raised intracranial pressure, and often occurs with other symptoms
Vomiting
Can occur, especially with raised intracranial pressure
Note: Vomiting with headache can suggest raised intracranial pressure
Seizures
May be the first symptom, often as focal seizuresNote: Preventive anti-seizure medicine is not routinely recommended if you have never had a seizure; seizures are more common in tumours above the tentorium (supratentorial)
Balance / Walking Problems
Unsteady walking, balance problems, or frequent fallsNote: More frequent with tumours below the tentorium (infratentorial)
Vision Changes
Blurred or double visionNote: Vision changes depend on tumour location and raised intracranial pressure
Behaviour / Personality Changes
Personality or cognitive changesNote: Early subtle changes may be missed, especially in children
Hormone-related symptoms
May result in reduced libido, menstrual changes, or fatigue
Note: Can occur when tumours affect the hypothalamus or pituitary gland
Other Focal Symptoms
Weakness or numbness on one side of the body, facial weakness or droopingNote: Symptoms mainly reflect tumour location, while tumour grade influences how quickly symptoms develop or worsen
Neurological and Cognitive Changes
The symptoms of a brain tumour depend largely on where the tumour is located. The brain is divided into four lobes, and each lobe is responsible for different functions. When a tumour grows in a particular lobe, it can affect the functions controlled by that area. For example:
The frontal lobe controls higher-order functions such as personality and behaviour, decision-making, problem-solving, speech and language, and voluntary movement, including motor functions. A tumour in this region may affect behaviour and lead to symptoms such as apathy, poor planning, inappropriate social behaviour, motor weakness and difficulty initiating movements, or speech problems.
The parietal lobe is responsible for sensory perception, including touch, pain, and temperature. It also helps you understand space and direction and integrates visual information. A tumour in this area may cause seizures, numbness, or tingling in parts of the body. It can affect every day learned tasks such as getting dressed or using familiar tools. You may also experience difficulty reading or writing, or difficulty with calculations, problems judging distance, confusion between left and right, or difficulty recognising objects by touch.
Carers may notice changes in personality or behaviour over time. Some changes reflect direct effects on brain networks, while others reflect stress, sleep disruption, or medication effects. These changes can vary in pattern and severity throughout the illness. They may also be influenced by factors such as the emotional impact of a brain tumour diagnosis, prognosis, and social or environmental stressors, which can interact with the neurological effects of the tumour and affect how symptoms present.
How Tumours Interact with the Brain
Cellular Origins and Growth
Understanding the biology behind a diagnosis helps clarify why certain common symptoms appear. Many primary tumours originate from glial cells, which support and protect neurons, although other tumour types can develop from different cells in the brain. While some of these may be benign tumours, they still pose a risk because the skull is a rigid space. Even slow-growing tumours can eventually cause symptoms by increasing pressure within the skull or by affecting nearby brain structures.
Structural Impact and Nutrient Supply
A tumour’s impact depends on how it grows and interacts with surrounding brain tissue. As they grow, they may form new blood vessels to support their growth, a process known as angiogenesis. Because the brain controls movement, sensation, and coordination, disruption of these pathways can lead to symptoms such as weakness, numbness, or loss of coordination.
Managing Different Tumour Types
The symptoms caused by a mass also depend on its origin. While primary tumours start in the brain, secondary tumours (metastases) arrive via the bloodstream from other organs. Treatment depends on the tumour type and may include surgery, radiation therapy, chemotherapy, or a combination of these approaches. Radiotherapy uses targeted energy to control tumour growth and reduce its impact on surrounding brain tissue.
Advanced or End-Stage Symptoms
As brain tumours progress, neurological symptoms may become more severe and widespread, particularly in advanced or end-stage disease. Similar neurological symptoms may also occur in advanced cancer due to brain metastases. Patients may experience a wide range of symptoms, including:
- Drowsiness or reduced levels of consciousness
- Difficulty communicating or speaking
- Reduced mobility or increasing dependence on others
- Difficulty swallowing, nausea, or vomiting
- Urinary incontinence
- Persistent headaches and other pain related to reduced mobility or advanced illness
- Confusion and delirium due to progressive neurological decline
- Seizures and muscle weakness
- Focal neurological deficits affecting specific functions
At this stage, interventions focused on comfort, symptom control, and quality of life are essential for both patients and their caregivers and can significantly help reduce symptom burden. Palliative care and support play a crucial role at this stage to relieve symptoms and improve daily comfort.
When to See a Doctor
While advanced or end-stage brain tumours may cause severe and obvious symptoms, earlier signs may be subtle, making it important to recognise warning signs that should not be ignored. Headaches on their own are usually not a sign of a brain tumour unless they occur alongside other symptoms such as nausea or vomiting.
A physician will evaluate your symptoms alongside known risk factors to determine the necessity of imaging. Early medical evaluation, without delaying the reporting of symptoms, is important for earlier diagnosis and access to appropriate treatment.
Patients may also discuss the possibility of participating in clinical trials to access emerging therapies. In people with a history of cancer, new or unexplained symptoms of the brain and nervous system may raise concern for the spread of cancer to the brain.
Some “red-flag” symptoms that require urgent medical attention include:
- A progressively worsening and persistent headache, especially one that is worse on waking.
- Sudden changes in behaviour or thinking abilities, particularly if these changes are very different from the person’s usual personality.
- New or recurrent seizures associated with altered awareness.
- Sudden weakness or paralysis, especially affecting one side of the body.
While these symptoms can be caused by many conditions, new, persistent, or severe neurological changes should always be assessed promptly by a healthcare professional. Brain tumours are rare compared with many other serious conditions, but persistent neurological symptoms should never be ignored.
Whether you’re facing a new diagnosis or supporting a loved one, help is available. Our Support Information pages provide resources and guidance to help you manage the symptoms of brain cancer treatment and support you through every stage of your brain cancer journey.
References
Alther, B., Mylius, V., Weller, M., & Gantenbein, A. (2020, 2020/07/01). From first symptoms to diagnosis: Initial clinical presentation of primary brain tumors. Clinical and Translational Neuroscience, 4(2), 2514183X20968368. https://doi.org/10.1177/2514183X20968368
Armstrong, T. S., Vera-Bolanos, E., Acquaye, A. A., Gilbert, M. R., Ladha, H., & Mendoza, T. (2016). The symptom burden of primary brain tumors: evidence for a core set of tumor- and treatment-related symptoms. Neuro-Oncology, 18(2), 252-260. https://doi.org/10.1093/neuonc/nov166
Ghandour, F., Squassina, A., Karaky, R., Diab-Assaf, M., Fadda, P., & Pisanu, C. (2021). Presenting Psychiatric and Neurological Symptoms and Signs of Brain Tumors before Diagnosis: A Systematic Review. Brain Sciences, 11(3), 301. https://www.mdpi.com/2076-3425/11/3/301
Lee, J. W., Wen, P. Y., Hurwitz, S., Black, P., Kesari, S., Drappatz, J., Golby, A. J., Wells, W. M., III, Warfield, S. K., Kikinis, R., & Bromfield, E. B. (2010). Morphological Characteristics of Brain Tumors Causing Seizures. Archives of Neurology, 67(3), 336-342. https://doi.org/10.1001/archneurol.2010.2
McDougall, E., Dhillon, H. M., Piil, K., Breen, L. J., Nowak, A. K., Nordentoft, S., Kjærgaard, S., & Halkett, G. K. B. (2025, 2025/10/17). Defining the symptoms of personality and behaviour changes in brain tumour patients and their impact on caregivers. Supportive Care in Cancer, 33(11), 959. https://doi.org/10.1007/s00520-025-09966-w
Reulecke, B. C., Erker, C. G., Fiedler, B. J., Niederstadt, T.-U., & Kurlemann, G. (2008). Brain Tumors in Children: Initial Symptoms and Their Influence on the Time Span Between Symptom Onset and Diagnosis. Journal of Child Neurology, 23(2), 178-183. https://doi.org/10.1177/0883073807308692
Walbert, T., & Khan, M. (2014, 2014/04/01). End-of-life symptoms and care in patients with primary malignant brain tumors: a systematic literature review. Journal of Neuro-Oncology, 117(2), 217-224. https://doi.org/10.1007/s11060-014-1393-6
Wilne, S. H., Dineen, R. A., Dommett, R. M., Chu, T. P. C., & Walker, D. A. (2013). Identifying brain tumours in children and young adults. BMJ : British Medical Journal, 347, f5844. https://doi.org/10.1136/bmj.f5844