Defining the Causes
Smell loss affects millions of people worldwide with nearly 1 in 4 (23%) of Americans over the age of 40 report a change in their ability to smell. Many people take their smell for granted, but even partially losing your sense can alter your quality of life leading to frustration, sadness, and depression. In addition, it hinders your ability to detect rotten/spoiled food, natural gas leaks, or other environmental hazards.
Defining Smell Loss/Distortion
Anosmia: Complete loss of smell. Can either be acquired (from infections, smoking, etc) or congenital (present from birth- rare). Characterized by swelling or blockage that prevents odors from reaching the top of the nose.
Hyposmia: Reduced sense of smell. A decreased ability to detect aromas and odors through your nose.
Parosmia: Distorted sense of smell. Experience loss in scent intensity and can not smell the full range of odors around you.
Phantosmia: Experience smells that are not usually there. Known as an olfactory hallucination.
Causes of Smell Loss
Some issues result in temporary loss while others can lead to long term smell loss.
- Infection or virus: cold, flu, COVID-19, sinusitis
- Head trauma
- Nasal polyps: growths within the tissues in the nose
- Ageing: common to experience altered smell the older a person gets
- Exposure to harmful chemicals: pesticides or solvents
- Poor air quality
- Neurodegenerative Conditions: Brain tumors, Parkinson's disease, Alzheimer's disease
***"Idiopathic" smell loss: when there is no identified cause
How do we Smell?
Our ability to smell is a beautiful connection between our nose and our brain.
Smell occurs when molecules of a substance, for example a rose petal, mix with the air. When these molecules enter our nose, they activate the olfactory nerve cells located in the nasal cavity. The nerve endings send messages to the brain communicating what we are smelling.
How does smell loss affect me?
Research has shown that people with smell loss report high rates depression, anxiety, social isolation, and emotional problems. Our sense of smell is closely tied to the experiences and interactions we have with the world, thus experiencing smell loss can impact, everything.
In addition, smell loss limits the ability to detect hazards such as rotten food, natural gas spills, or burning.