If a person experiences a burning smell when there is no source for the odor, it can be caused by a condition called phantosmia, states Dr. Weil. This is also known as olfactory hallucination, which means that the smell is not real. Phantosmia may be a symptom of certain conditions, according to the Mayo Clinic.
Phantosmia can present with different types of imaginary smells that can be pleasant or malodorous like a burning smell. The symptom can be linked to brain problems like temporal lobe seizures or a brain tumor. Phantom smells can also be associated with head injuries, nasal polyps, tumors and Parkinson's disease, reports MedicineNet. Because it may be connected to an illness, people with phantosmia should be diagnosed by a doctor.