The tell-tale sign of brain cancer doctors say you shouldn't ignore

THE possibility of developing brain cancer is an admittedly terrifying thought. However, brain cancer and brain tumours are incredibly rare, with the American Cancer Society putting your lifetime risk at less than 1%. Still, knowing the number-one sign of brain cancer can help set your mind at ease, putting you on the course to treatment if you need it and hopefully preventing catastrophizing when you don’t.

Beyond the fact that it’s very rare, it’s also helpful to know that there are very few factors that increase your risk of developing brain cancer.

“The only known risk factors are exposure to radiation and/or a family history with genetic predisposition to certain tumours or cancers,” said Alyx B. Porter, M.D., a neuro-oncologist and professor of neurology at Mayo Clinic.

Here, discover the most common signs of brain cancer that you should know, plus some more rare secondary symptoms and when it might be worth giving your physician a call.

Most common signs of brain cancer

Seizures

If you have a seizure and you don’t have a known disorder that causes them, Dr. Porter said that’s a definite signal to talk to a doctor, as it is the most common symptom of brain cancer.

According to the American Cancer Society, as many as 50% of people with brain tumours will experience a seizure at some point. However, there are many possible causes of seizures—the American Cancer Society adds that less than 10% of first seizures are caused by a brain tumour. Still, it’s a sign that something is likely wrong in your skull and worth further follow-up.

Strange sensations in your limbs

After seizures, Dr. Porter said that this is the next most common sign of brain cancer. A gradual loss of sensation or mobility in a limb, over a period of days or weeks, or weakness in a limb, is a potential symptom of a brain tumour, she explained. Per the American Cancer Society, this would be caused by a tumour in the large, outer part of the brain and would often appear only on one side of your body.

Headaches

Headaches are incredibly common and have a host of possible causes. But if you get a "progressive headache that doesn’t respond to medications or is new," Dr. Porter said that this may point toward a brain tumour (the American Cancer Society says that about half of people with tumours experience headaches).

Anything headache-related that is not normal for you, such as if you’re suddenly getting headaches more frequently than usual or if they’re worse than you’ve ever had, could be a sign that something is up.

Difficulty understanding people

Suddenly having trouble comprehending what people are saying or expressing your own thoughts? That may be a symptom, said Dr. Porter. According to the American Brain Tumour Association, you may also experience cognitive changes like difficulty reading or writing, issues with short-term memory, or struggling to multitask or plan and organise your thoughts.

Vision issues

Dr. Porter said a change in your vision is another common symptom of a brain tumour. Per the American Brain Tumour Association, these symptoms can develop if you have a tumour near your occipital lobe or optic nerve. So if things suddenly look all blurry, or you have double vision, sensitivity to light, or notice a problem with your peripheral vision, those are warning signs to pay attention to.

Secondary brain cancer symptoms

In addition to those above, other symptoms can be caused by brain cancer. Still, Dr. Porter cautioned that if you experience any of the three below, you'll want to rule out other causes first, as they can be related to a host of possible health conditions. If you’re experiencing them in addition to one or more of the symptoms above, it’s more likely that they’re all related.

Changes in balance: Are you suddenly a-kilter or losing balance when you haven’t before, or are you having difficulty walking? This could happen with a brain tumor, but balance problems can also be caused by inner ear disorders, migraines, heart disease, and nerve damage, among other conditions, per the Cleveland Clinic.

Fuzziness or confusion: If you’re having trouble remembering or focusing on everyday things, there’s a slight chance that it could be a symptom. Keep in mind, though, that brain fog can be a symptom of so many things, including stress, lack of sleep, and menopause.

Sudden personality changes: Becoming suddenly aggressive or sluggish, for instance, would be a rare symptom of a brain tumour, per the American Brain Tumour Association. But these could also be attributed to a mental health disorder.

When to call your doctor

“I recommend a consultation with a physician when symptoms arise outside of your usual experience with your health,” said Dr. Porter. “At the very least, a baseline assessment can provide significant value should changes occur in the future. “

Remember that any of the symptoms above could be (and probably are) due to something else entirely and don’t necessarily mean you have brain cancer. That said, it’s important to take it seriously when your body is giving you a new signal that something might be off. And if you experience more than one of the symptoms above, you should certainly make an appointment right away.