Anosmia, or the loss of the sense of smell, is common and affects most people at some point in life. It has many causes some of which are correctable after an accurate diagnosis.

Common Causes

  • Blockage: congestion and obstruction of the nose due to inflammation, allergy, masses, or nasal polyps.
  • Upper respiratory tract infection: viruses including parainfluenza, and recently reports of infection with COVID-19, a novel coronavirus.
  • Trauma: head injuries can impact the nerves that transmit smell signals to the brain.
  • Chemical and medicine induced: zinc, toxic exposures, and certain oral medications.
  • Hormone related: Thyroid gland dysfunction, Kallmann syndrome.
  • Brain mass: Frontal lobe mass (Foster Kennedy Syndrome).
  • Neurological problems: Alzheimer’s and Parkinson diseases.
  • Age related loss (presbyosmia).

In addition to affecting taste, the loss of smell can negatively impact your quality of life and may even be a sign of a more serious medical problem. In addition, it can put your safety at risk if you are unable to smell dangerous substances such as gas leaks.

A careful history and physical examination can oftentimes reveal a cause which can be treatable to restore the sense of smell. This may include an examination with an endoscope or radiographic imaging studies.