Anosmia (Loss of Smell) – Know its Causes and Treatment
by MedPlus Team, February 4, 2020
The medical term for “loss of smell” is ‘Anosmia’. Anosmia is a condition where partial or complete loss of smell. This condition could be either temporary or permanent. Temporary anosmia is usually due to irritation caused on the nose lining caused due to allergies/cold.
Causes of Anosmia:
Anosmia usually occurs due to swellings or blockages in the nose which prevents odor from entering the nose. Alternatively, it occurs due to the failure in the system that sends signals from the nose to the brain. Let us see the prime causes in detail:
1. Sinus infection
2. Common cold
4. Flu or influenza
5. Allergies, allergic rhinitis
6. Chronic congestion not related to allergies (known-allergic rhinitis)
Anosmia caused due to common cold usually leads to partial anosmia and this case usually subsides by itself when cold subsides. In case of blocked nasal passage, air cannot pass through the nose which is probably due to:
2. Nasal Polyps
3. Bone deformities inside the nose or a nasal septum
In case of damage to the brain or any nerve, the receptors in the nose that contribute to carrying the information from the nose to the brain might be damaged. This may cause the patient not to smell. This damage in receptors could happen due to various reasons such as:
1. Growing old
2. Alzheimer’s disease
4. Brain tumors
5. Huntington’s disease
6. Hormonal problems
7. Under-active thyroid
8. Medications including some antibiotics, and hypertensive medicines
9. Multiple sclerosis
10. Parkinson’s disease
13. Exposure to the chemicals that irritate the nose
14. Brain or head injury
15. Vitamin deficiencies and malnutrition
16. Radiation therapy
17. Long term use of alcohol
There are some cases where some children born with anosmia due to some genetic abnormalities. This is referred to as congenital Anosmia.
Diagnosis of Anosmia:
Loss of smell is immeasurable. Your doctor will examine your nose, current symptoms, health history and may also perform a complete physical examination of your body. Some frequently used tests are:
1. CT scans – which use x-rays to create a detailed image of the brain.
2. MRI scans – which use magnets and radio waves to view the brain.
3. Nasal endoscopy to view the internal side of the nose.
4. X-ray of the skull.
Complications of the Condition:
1. People with anosmia generally loose interest to eat which leads to malnutrition and weight loss
2. People with this condition should make sure to have a functioning smoke alarm (a device that senses smoke) at all times at their homes.
3. They must be cautious with food storage and the use of natural gas because it’s hard for them to detect spoiled foods and identifying gas leakage.
1. Pick the items that are properly labeled with expiry dates
2. Always read labels on chemicals for kitchen cleaners and insecticides
3. As a safety measure, use electronic appliances with start/stop options – in case you miss out a burning (or other) smell
Treatment For Anosmia:
Treatment is given based on the cause. If you have a cold or an allergy, your anosmia will usually heal on its own within a few days (as and when your cold subsides). If anosmia persists even after your cold is healed, you might want to consult your doctor. Treatment for Anosmia if effected with nasal irritation includes:
3. Steroid nasal sprays
4. Antibiotics for bacterial infection
5. Reducing exposure to nasal irritants and allergens
6. Discontinue smoking
If anosmia is caused by a nasal obstruction that can be treated by removing the particle that obstructs your nasal passage. This involves the removal of nasal polyps, straightening the nasal septum, or clearing out the sinuses. Old people get effected with anosmia permanently. Currently, there is no treatment for congenital anosmia.