Seven unexpected health issues that could be an early warning sign of a brain tumour

Most of us experience occasional forgetfulness, have annoying headaches, or feel more tired than usual. It’s part of daily life - often down to stress, long days at work, or not enough sleep. But in some cases, these everyday issues can mask something more serious.

Brain tumours can occur at any age, and while they’re rare, spotting symptoms early can make a crucial difference to how quickly they’re diagnosed and treated.

Doctors emphasise that these symptoms don’t automatically mean a brain tumour - there are far more common causes for each of them. But if something doesn’t feel quite right, or a symptom lingers and changes over time, it’s worth seeking medical advice.

Here are seven early warning signs that are often overlooked, based on research by neuro-oncologists, patient accounts, and CCLG data.

One of the less obvious early warning signs can be trouble expressing yourself verbally. Patients in research by Dr Laura Standen and Professor Suzanne Scott (The Conversation) described struggling to recall words, form sentences, or keep up in conversations. Some said it felt “odd and out of character,” leading them to dismiss the symptom initially.

Word-finding difficulties may occur when tumours affect language-processing areas in the brain, such as the left frontal or temporal lobes. While fatigue, stress, or anxiety can sometimes explain brief lapses, persistent or suddenly appearing language issues - especially if paired with other cognitive changes - should prompt further investigation.

Brain fog - characterised by difficulty concentrating, slow thinking, forgetfulness, or mental fatigue - is another symptom often mistaken for common life stressors. One patient initially had their confusion attributed to menopause, while others assumed it was just lack of sleep or workplace stress.

Dr Shiao-Pei Weathers, M.D., explains that when brain fog is accompanied by neurological symptoms like speech or vision changes, it may indicate that a tumour is affecting cognitive areas of the brain. This can also explain why patients sometimes forget appointments or why their decision-making seems impaired, making early recognition difficult.

Patients frequently report new or unusual sensations such as numbness, tingling, or a “pins-and-needles” feeling. What raises concern is when these symptoms affect only one side of the body. For example, one patient experienced numbness on half of their tongue and the inside of their mouth, while another noted tingling down one arm.

These sensations can occur when a tumour interferes with the brain’s motor or sensory regions, which control movement and perception across different parts of the body. While they may also result from trapped nerves, migraines, or poor circulation, neurologists advise that new, persistent, or one-sided sensory changes always be assessed promptly.

Vision disturbances can be subtle yet significant. One patient reported to Dr. Weathers' research that they noticed double vision while watching television, and another described straight lines appearing curved. “I thought they’d sent us a load of dodgy mugs because they’re all oval,” they recalled.

Visual symptoms occur when tumours press on the occipital lobe or optic pathways. They can include blurred vision, double vision, loss of peripheral vision, or even a greying out of vision when standing up. Sudden visual distortions, particularly when combined with headaches, weakness, or speech difficulties, should be investigated as they may indicate pressure on the brain’s visual centres. Opticians can sometimes spot signs of increased intracranial pressure during routine eye tests, making them an unexpected but useful first point of contact.

Changes in hand-eye coordination, such as messy handwriting or difficulty performing fine motor tasks, may signal a tumour affecting the cerebellum or motor cortex. Patients have reported sudden moments where their handwriting became illegible, or they struggled with everyday actions like buttoning a shirt.

While fatigue or distraction can cause temporary lapses, persistent deterioration in fine motor skills, balance, or coordination should prompt neurological evaluation. In children, this can be particularly noticeable when toddlers who had started walking begin to crawl again or show unsteady movement.

Even subtle shifts in mood, irritability, or motivation can be early indicators. One patient described feeling unusually irritable and unmotivated, initially thinking it was burnout. Brain tumours affecting the frontal or temporal lobes can influence personality, behaviour, and emotional regulation.

Personality changes are often first noticed by friends or family. Dr Standen and Professor Scott note that alterations such as sudden apathy, irritability, or loss of interest in hobbies should not be ignored - especially when accompanied by other neurological changes like speech difficulties or memory lapses.

Headaches are the most commonly recognised symptom of a brain tumour, but what sets tumour-related headaches apart is their pattern and persistence. Patients describe headaches that feel different from their usual experiences, intensify in the morning, or worsen when lying down, bending, or coughing.

Shelby Espinosa, diagnosed with a medulloblastoma at 22, recalled a headache so intense that she “had to stop talking and just hold my head.” Another patient, Sean O’Brien, experienced blind spots alongside worsening headaches, a warning of fluid buildup in the brain. According to Dr Weathers, headaches lasting days or weeks, especially with nausea, vomiting, or other neurological symptoms, should be taken seriously.