Which conditions can cause smell hallucinations?

Smell hallucinations, which involve perceiving odors that are not actually present, can occur in association with several brain and mental health conditions. According to medical research, these experiences may be linked to:

• Epilepsy: Certain types of seizures can manifest as olfactory hallucinations.
• Tumours: The presence of a brain tumour can disrupt normal sensory processing and lead to these perceptions.
• Depressive illnesses: Individuals suffering from clinical depression may also experience smell hallucinations as a symptom of their condition.

It is important to note that while these hallucinations are related to brain disorders, other issues such as head injuries or local nasal diseases typically result in a reduced sense of smell or total loss of smell (anosmia) rather than hallucinations.1