Signs of Brain Cancer: Causes, Symptoms, and When to Worry
Learn the common signs of brain cancer, including headaches, seizures, and personality changes. Understand the causes, risk factors, and when to seek medical help.
Written by Dr. M L Ezhilarasan
Reviewed by Dr. Rohinipriyanka Pondugula MBBS
Last updated on 18th Sep, 2025
Introduction
The human brain is the command centre for everything we do, think, and feel. So, when something goes wrong within this intricate organ, the signs can be as varied and complex as its functions. Understanding the signs of brain cancer is the first step towards seeking timely medical help. This article demystifies what leads to these symptoms, separating fact from fiction about the causes and risk factors. We’ll explore everything from the common warning signs to the biological mechanisms at play, empowering you with knowledge and clarity.
Many symptoms of a brain tumour are subtle and easily mistaken for less serious conditions. However, recognising specific patterns and combinations is crucial. This guide will walk you through the different categories of symptoms, explain what causes them on a physiological level, and outline the known and potential risk factors that can lead to the development of brain cancer. Our goal is not to alarm you, but to inform you, so you can make empowered decisions about your health.
What Are the Most Common Signs of Brain Cancer?
The signs of a brain tumour are broadly categorised into two groups: general symptoms caused by increased pressure inside the skull (intracranial pressure) and focal symptoms caused by the tumour pressing on or invading specific areas of the brain.
General Symptoms Caused by Pressure Inside the Skull
As a tumour grows, it takes up space within the rigid confines of the skull. This increases pressure, which affects brain function globally. Swelling around the tumour (oedema) further contributes to this pressure.
Headaches: The Most Misunderstood Sign
While headaches are extremely common, brain cancer headaches often have distinct characteristics. They may be worse in the morning or wake you from sleep, worsen with coughing, sneezing, or exercise, and gradually become more frequent and severe over time. However, it is important to note that not all brain tumours cause headaches, and not all severe headaches are tumours.
Nausea and Vomiting Without Explanation
Unexplained nausea or vomiting, particularly in the morning, can be a sign of increased intracranial pressure. This occurs because the pressure affects the brainstem's vomiting centre.
Drowsiness and Altered Consciousness
As pressure increases, it can lead to a general feeling of fatigue, drowsiness, and even episodes of confusion or unconsciousness. This is a serious sign that requires immediate medical attention.
Focal Symptoms: When the Tumour's Location Matters
The specific functions controlled by the area where the tumour is located will be disrupted. This is why symptoms can vary dramatically from person to person.
Seizures in a Person With No History
A seizure is often the first sign of a brain tumour. It occurs when the tumour's abnormal cells disrupt the brain's normal electrical activity. A new-onset seizure in an adult is always a reason to see a doctor.
Speech and Vision Problems
A tumour near the brain's language centres can cause aphasia (trouble finding words, understanding speech). One pressing on the optic nerves can cause blurred vision, double vision, or even loss of peripheral vision.
Consult a Oncologist for Personalised Advice
Weakness or Numbness on One Side of the Body
Tumours affecting the motor cortex or sensory pathways can cause progressive weakness, numbness, or a "pins and needles" sensation typically on one side of the face, arm, or leg.
Cognitive and Personality Changes
Perhaps some of the most distressing signs are changes in personality, behaviour, or cognitive ability. This might include increased irritability, apathy, memory loss, or poor judgement, often noticed first by family members.
What Actually Leads to These Signs? The Root Causes
The "signs" are the body's response to the presence of the tumour. But what leads to the tumour itself? The causes are primarily genetic at the cellular level.
Primary Brain Tumours: Where It All Begins
These tumours originate in the brain itself or its immediate surroundings (like the meninges or pituitary gland).
Genetic Mutations: The Blueprint Goes Awry
The primary cause of brain cancer is DNA mutations within normal brain cells. These mutations instruct the cells to grow and divide rapidly and to continue living when healthy cells would die. This leads to a mass of abnormal cells—a tumour. In most cases of primary brain cancer, it is unclear what triggers these initial genetic mutations. This is a key area of ongoing research in oncology.
The Role of Inherited Syndromes and Family History
A small percentage of brain tumours are linked to known genetic syndromes that run in families. These include Neurofibromatosis type 1 and type 2, Von Hippel-Lindau disease, and Li-Fraumeni syndrome. However, these account for a minority of cases.
Secondary (Metastatic) Brain Cancer
This is actually the most common type of brain cancer. It does not start in the brain but is caused by cancer cells from another part of the body (like the lung, breast, colon, or skin) breaking away, travelling through the bloodstream or lymphatic system, and forming a new tumour (metastasis) in the brain. The signs are the same as a primary tumour, but the origin is different.
Known Risk Factors That Can Increase Likelihood
While the cause is often unknown, several factors can increase risk.
Exposure to Ionising Radiation
The clearest environmental risk factor is exposure to high-dose ionising radiation, such as that received from radiation therapy used to treat other cancers or from atomic bomb fallout. Common radiation, like from mobile phones or power lines, has not been conclusively proven to increase risk, though research continues.
Age, Gender, and Immune System Status
Risk increases with age, though some tumours are more common in children. Some types are more prevalent in men than women. People with compromised immune systems, such as those with HIV/AIDS or organ transplant recipients on immunosuppressant drugs, have a higher risk of developing certain types of brain tumours.
From a Symptom to a Diagnosis: What to Expect
If you are experiencing persistent neurological symptoms that concern you, the diagnostic journey typically begins with a detailed neurological exam. If a brain tumour is suspected, the gold standard for diagnosis is an MRI (Magnetic Resonance Imaging) scan, which provides detailed images of the brain. A CT scan may be used in emergencies. A biopsy, where a sample of the tumour is surgically removed and analysed, is the only way to definitively diagnose the type and grade of the cancer. If you are experiencing persistent headaches, new seizures, or any sudden neurological changes, it is critical to consult a doctor. You can book a quick online consultation with a neurologist on Apollo24|7 to discuss your symptoms and determine the best next steps.
Few proven risk factors: High-dose radiation exposure and certain genetic syndromes are the strongest known risk factors.
Early evaluation is key: Do not ignore persistent or worsening neurological symptoms. Early diagnosis can significantly impact treatment options and outcomes.
Conclusion: Empowerment Through Awareness
Understanding the signs of brain cancer and what leads to them is not about fostering fear, but about promoting awareness and proactivity. Our brains are resilient, but they also require our vigilance. Many symptoms can be caused by far less serious conditions, but their persistence is a signal that should not be ignored.
Knowledge is the first line of defence. By recognising the patterns—headaches that change or worsen, new neurological deficits, unexplained nausea—you empower yourself to seek timely medical advice. The field of oncology is advancing rapidly, with new treatments offering hope and improved outcomes. If you have any concerns about your health or that of a loved one, the most important step is to start a conversation with a healthcare professional. Apollo24|7 makes it easy to connect with experienced neurologists and oncologists online for an initial consultation, providing guidance and peace of mind from the comfort of your home.
Consult a Oncologist for Personalised Advice
Consult a Oncologist for Personalised Advice
Dr Gowshikk Rajkumar
Oncologist
10 Years • MBBS, DMRT, DNB in Radiation oncology
Bengaluru
Apollo Clinic, JP nagar, Bengaluru
Dr. Rupam Manna
Radiation Specialist Oncologist
4 Years • MBBS MD(RADIO THERAPY)
Barasat
Diab-Eat-Ease, Barasat
Dr Sunita Samleti
Oncologist
18 Years • M.D. (Pathology)- TN Medical College, Mumbai University, Mumbai, Mar 2005 M.B.B.S. Grant Medical College, Mumbai University, Mumbai, Oct 1999
Chinagadila
Apollo Hospitals Health City Unit, Chinagadila
Dr.sanchayan Mandal
Oncologist
17 Years • MBBS, DrNB( MEDICAL ONCOLOGY), DNB (RADIOTHERAPY),ECMO. PDCR. ASCO
Kolkata
Dr. Sanchayan Mandal Oncology Clinic, Kolkata
Dr. Sanchayan Mandal
Oncologist
17 Years • MBBS, DNB Raditherapy, DrNB Medical Oncology
East Midnapore
VIVEKANANDA SEBA SADAN, East Midnapore
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Frequently Asked Questions
What are the very first signs of a brain tumour?
The very first sign can be highly variable. For some, it is a new type of headache that does not go away. For others, it could be a seizure, a gradual loss of sensation in a limb, or subtle changes in memory or personality. There is no single 'first sign,' but any persistent, unexplained neurological symptom warrants a doctor's visit.
Can stress cause brain cancer?
No, there is no conclusive scientific evidence that psychological stress directly causes brain cancer. The primary causes are genetic mutations. However, stress can exacerbate symptoms like headaches, which might make existing issues feel worse.
Are all brain tumours cancerous?
No. Tumours can be benign (non-cancerous) or malignant (cancerous). Benign tumours grow slowly and are less likely to invade surrounding tissue, but they can still be serious if they press on critical areas of the brain and cause symptoms.
How long can you have a brain tumour before noticing symptoms?
It depends entirely on the tumour's location, type, and growth rate. A slow-growing benign tumour in a 'silent' area of the brain might go unnoticed for years. A fast-growing malignant tumour can cause symptoms over weeks or months.
Who is most at risk for developing a primary brain tumour?
While anyone can develop a brain tumour, risk factors include age (risk increases as you get older, though some tumours are more common in children), exposure to high-dose ionising radiation, a family history of certain genetic syndromes, and having a compromised immune system.