You’re having headaches. Or maybe your vision’s been a little off. Your balance feels strange. And then the thought hits you: Could it be a brain tumour?
Before panic sets in, know this—many conditions can mimic the symptoms of brain cancer. That’s why doctors go through several steps to carefully figure out what’s really going on.
Let’s walk through how they do it.
Why Diagnosing Brain Conditions Is So Tricky
Here’s the thing: the brain is your command centre. So when something’s off, the signals can be vague and confusing. A person with a tumour might feel dizzy. But so might someone with low blood sugar—or anxiety.
Brain cancer doesn’t come with a neat little checklist. Its symptoms often look like many other, much less dangerous issues. That’s what makes diagnosis both fascinating and frustrating.
When Symptoms Overlap: Brain Cancer vs. Other Disorders
Let’s say someone shows up with sudden vision changes, memory problems, or seizures. Could it be:
- A brain tumour?
- A stroke?
- Multiple sclerosis?
- A bad migraine?
- Even just stress or anxiety?
The truth is, all of those are possible.
Doctors don’t jump to conclusions. Instead, they use your symptoms as clues—then look for evidence. That’s where testing comes in.
Common Signs of Brain Cancer (And How They Can Mislead You)
Here’s a quick look at symptoms often associated with brain tumours:
- Persistent headaches (especially worse in the morning)
- Nausea or vomiting without reason
- Seizures (new onset, particularly in adults)
- Personality or behaviour changes
- Weakness or numbness in limbs
- Trouble speaking or understanding speech
- Blurred or double vision
But here’s the kicker: none of these signs are unique to brain cancer.
For example, chronic migraines can cause nausea and visual disturbances. Stress can change your personality. Seizures? They could be from epilepsy.
That’s why doctors never rely on symptoms alone to diagnose brain tumours.
First Steps: What Happens When You See a Doctor
It usually starts with a conversation.
Your doctor will ask:
- When did the symptoms begin?
- How often do they happen?
- Any history of injury, infection, or family history of neurological diseases?
- Are the symptoms getting worse—or staying the same?
From there, they’ll likely do a physical exam, followed by something more specific: a neurological exam.
The Role of Neurological Exams
This part may feel a bit like a coordination game.
Doctors might:
- Shine a light in your eyes
- Ask you to touch your finger to your nose
- Test your grip strength
- Watch how you walk
They’re checking your cranial nerves, reflexes, balance, and coordination. Even small abnormalities can suggest where the brain might be affected—and whether more advanced imaging is needed.
Imaging Matters: CT Scan vs. MRI
So how do doctors actually “see” what’s going on in your brain?
Here’s how:
- CT scan (Computed Tomography): Quick and widely available. Useful if there’s a suspected bleed or urgent issue.
- MRI (Magnetic Resonance Imaging): Offers a much more detailed look. Especially good at spotting tumours, swelling, or subtle abnormalities.
If there’s something suspicious—like a mass—they’ll look closer. But if everything looks normal? They may explore other causes.
Functional Brain Tests: EEG and PET Scans
Sometimes, even with imaging, the picture isn’t clear.
That’s when doctors might bring in tools like:
- EEG (Electroencephalogram): Measures brain wave activity. Especially helpful if seizures are a concern.
- PET Scan (Positron Emission Tomography): Can detect cancer activity and differentiate between active tumours and scar tissue.
Still, none of these can give a 100% yes or no answer about cancer. For that, doctors need tissue.
Blood Work and Biomarkers: Can a Blood Test Detect Brain Cancer?
We’re not quite there yet.
Although some experimental tests are exploring blood-based “biomarkers” for brain tumours, there’s currently no single blood test that can definitively detect brain cancer.
However, blood tests are still useful. They can:
- Check for infection or inflammation
- Rule out metabolic issues or autoimmune diseases
- Assess your overall health before more invasive tests
The Gold Standard: When Is a Brain Biopsy Needed?
If imaging suggests a tumour—and especially if it’s growing or causing symptoms—doctors may recommend a biopsy.
That means removing a small piece of the brain tissue for analysis.
Sounds scary, right?
There are two main ways this is done:
- Stereotactic biopsy: A small hole is drilled in the skull to take a tiny sample.
- Surgical biopsy (open surgery): If the tumour is accessible and needs to be removed anyway, they take a larger portion during surgery.
This is the only way to confirm if a tumour is cancerous, what type it is, and how aggressive it might be.
Diagnosing “Look-Alikes”: Infections, Inflammation, and Benign Tumors
Not all brain lesions are cancer.
Sometimes, what looks like a tumour on a scan turns out to be:
- A brain abscess (an infection)
- Multiple sclerosis
- A benign tumour like a meningioma or acoustic neuroma
- Autoimmune encephalitis
Each of these conditions can cause neurological symptoms—and may even appear similar on imaging. That’s why diagnosis is often a process of elimination, not instant confirmation.
How Long Does Diagnosis Usually Take?
You might think it’s a quick process: scan, test, answer.
But in reality, it can take days to weeks, depending on:
- How clear the symptoms are
- The availability of imaging
- Whether a biopsy is needed
- Coordination between specialists (neurologist, neurosurgeon, oncologist)
Waiting can be tough. But taking the time to get the right diagnosis is critical—because the treatment depends on it.
When to Get a Second Opinion
Let’s be honest—when it comes to something as serious as your brain, a second opinion isn’t just okay. It’s smart.
You should consider one if:
- You feel rushed into treatment
- The diagnosis is unclear or feels inconsistent
- You’re told surgery is necessary, and you’re unsure
Sometimes, another pair of expert eyes makes all the difference.
Final Thoughts
Brain cancer is a frightening possibility—but many people who fear the worst turn out to have something far more manageable.
Doctors don’t diagnose on instinct or guesswork. They piece together a puzzle made of symptoms, scans, tests, and sometimes tissue.
So if you’re dealing with strange symptoms, the best thing you can do? Speak up. Get checked. And keep asking questions.
References
- Brain Tumor Diagnosis: How Doctors Diagnose Brain Tumors, Mayo Clinic, 2024. https://www.mayoclinic.org/diseases-conditions/brain-tumor/diagnosis-treatment
- How Brain Tumors Are Diagnosed, American Cancer Society, 2023. https://www.cancer.org/cancer/brain-spinal-cord-tumors-adults/detection-diagnosis-staging/how-diagnosed.html
- Differential Diagnosis of Common Brain Tumor Mimics, Radiology Today, 2022. https://www.radiologytoday.net/archive/rtMJ22p10.shtml
- Blood Tests for Brain Tumors: What’s the Future?, Cancer Research UK, 2023. https://www.cancerresearchuk.org/about-cancer/brain-tumours/diagnosis/tests