Seven early brain tumour symptoms that are often dismissed

Everyone gets headaches. Everyone misplaces their phone or forgets a name now and then. Most of the time, these moments are harmless – the result of stress, fatigue, or just a busy mind. Yet they’re also examples of symptoms that can, in rare cases, signal something far more serious: a brain tumour.

So how can you tell the difference between a brain tumour and an ordinary tension headache, stress, a poor night’s sleep, or even a hangover?

As part of my research into earlier detection of brain tumours, I spoke with patients who had been diagnosed with one. Their experiences revealed a recurring pattern: both patients and GPs often dismissed early symptoms, which sometimes led to delays in diagnosis. This echoes findings from a previous study showing that people frequently overlook the warning signs. This is a problem because brain tumours require more invasive treatment if they’re not detected early.

Brain tumour symptoms often resemble everyday experiences – tiredness, stress, migraines, or the menopause – and overlap with much more common conditions such as anxiety, sinus infections, or chronic headaches.

When symptoms are vague or subtle, they can be easy to ignore or rationalise away. In a healthcare system where GP appointments can be difficult to get, patients may wait until symptoms become impossible to dismiss. One patient I spoke with told me: “I think probably I had symptoms about certainly two or three months before.”

Here are seven symptoms described by patients in my study, all of which were easy to mistake for something else.

It’s important to stress that having one or more of these symptoms doesn’t mean you have a brain tumour. But if something feels persistently “off” or out of character for your body, it’s worth getting checked.

1. Difficulty finding words

Some people noticed they struggled to think of specific words, form full sentences, or join in conversations without a delay. One patient said the experience felt “odd and out of character”, but they dismissed it at the time. Another wrote down their symptoms because they couldn’t say them out loud, knowing something was not quite right, but they “couldn’t explain to anyone what was going on”.

Word-finding problems can sometimes be linked to fatigue, stress, or even anxiety – but when they persist or come on suddenly, they may warrant further investigation.

2. Brain fog

Several patients described a general fogginess: difficulty focusing, thinking clearly, or remembering things. One booked a GP appointment but by the time it came around, they had forgotten why they’d made it, leading to a missed diagnosis.

Brain fog can have many triggers including menopause, poor sleep, or stress. One family member recalled: “When the symptoms came up, the answer was, ‘She’s going through the menopause.’” But when brain fog is accompanied by other neurological changes, such as speech or vision problems, it’s important to take note.

3. Numbness or tingling

Some people reported tingling or numbness that shifted around the body. Two patients noticed it affected only one side: “Half of my lower right side of my face and half my tongue, half of the inside of my mouth.”

This can happen when a tumour affects the brain’s sensory or motor control areas – the regions that send and receive signals to different parts of the body. While numbness can have other explanations (such as trapped nerves, poor circulation, or migraines), new or one-sided symptoms should always be checked.

4. Visual disturbance

Changes in vision were another early sign. One patient experienced double vision while watching TV and assumed they needed new glasses. Another said straight lines appeared curved. “I thought they’d sent us a load of dodgy mugs because they’re all oval, and people looked at me going: ‘What are you on about?’”

Visual changes can have many causes, including eye strain or migraines. But sudden or unusual distortions – especially when they occur alongside other neurological symptoms, such as headaches, dizziness, difficulty speaking, weakness or numbness on one side of the body, or problems with coordination – warrant medical attention.

5. Messy handwriting

Several patients noticed their hand-eye coordination changing. One recalled: “There was one moment when I couldn’t write. I was writing some notes in a meeting, and then it just became really messy writing.”

Small coordination changes can sometimes be due to fatigue or distraction, but consistent deterioration in writing, fine motor skills, or balance can signal problems with the brain’s motor control areas, which coordinate movements such as writing or buttoning a shirt.

6. Personality changes

Altered behaviour or mood can be subtle but telling. One patient thought their irritability and loss of motivation were just signs of burnout: “I didn’t really put two and two together. I just wanted to retire because I was fed up with it.”

It’s natural for personality to fluctuate with life changes or stress, but sudden or marked differences, especially alongside other symptoms, may indicate something more.

7. Headaches

Headaches are common and usually nothing to worry about. But for some of the patients I spoke with, the pain was constant and unrelenting, lasting for weeks. “It was lasting over a week, and it was pretty much coming on daily,” one said.

Improving diagnosis

My current research investigates whether new tools can help GPs identify potential brain tumours earlier. These include cognitive function tests, which can assess memory, attention and language skills and liquid biopsies: blood tests that look for fragments of tumour DNA circulating in the bloodstream.

Because brain tumour symptoms are so varied and often overlap with everyday conditions, diagnosis is difficult. Most of the time, the symptoms listed here will have nothing to do with cancer. But when unusual changes occur together or persist longer than expected, they shouldn’t be ignored.

The patients I spoke with all shared the same message: if something doesn’t feel normal for you, get it checked. Even if it turns out to be nothing serious, that reassurance is worth it.