Phantom odors & brain cancer

Updated July 19, 2017

Olfactory hallucinations are often referred to as phantom odours or phantosmia. You are experiencing a phantom odour when you detect a smell that is not really present. There are many things that can cause a phantom odour. In some cases, a phantom odour can be caused by a brain tumour.


What you smell and its intensity can vary by person. You may experience the smell in only one nostril or in both nostrils at the same time. Phantom smells are not masked by the smell or taste of food. All phantom odours can be a sign of a serious illness and should be discussed with your doctor.


The sense of smell is a chemical sense. Your nose picks up molecules in the air and translates those molecules into the sensation of smell. Your sense of smell can be damaged by exposure to chemicals, injury to your nose, seizures, infections and brain tumours located in the temporal lobe.


For a brain tumour to effect your sense of smell it must be located in the part of your brain that controls that sense. Your cerebrum is the largest part of your brain. All of your senses and movements are controlled by areas of your cerebrum. Your temporal lobe, a section of the cerebrum, controls your sense of hearing and smell. A brain tumour in the temporal lobe can affect your sense of smell and create a phantom odour.


Seizures are the most common sign of brain cancer located in the temporal lobe. Seizures can cause permanent damage to the brain. Seizures and tumour can damage the part of your brain that receives the message from your nose. Once damaged, your brain can misread the messages and smell odours that aren't present.


If you experience a phantom odour that will not go away or gets worse, see your doctor. Even if you do not have brain cancer, your phantom odour is being caused by something.

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About the Author

Mary Anne Ott is a cancer patient navigator in Ohio. She has a Bachelor of Arts in communications from Wright State University. Ott worked in the banking industry for six years as a personal banker and assistant branch manager before pursuing a career in health care.