Have You Lost Your Sense of Smell or Taste?

By Daniel Larson, MD

Having a decreased sense of smell (hyposmia) or complete loss of smell (anosmia) is more than an inconvenience; it can have a severe effect on your quality of life. Blunting your ability to sense any smell, good or bad, can leave you feeling foggy and disconnected from your surrounding environment. The loss of taste (which goes hand in hand with anosmia since 80% of taste perception is due to smells) can make eating a chore and even dangerous due to the inability to smell spoiled food.

Once you perceive that your ability to smell and taste has been diminished it is important to have this evaluated by an ENT specialist as soon as possible to look for potentially reversible causes.

Causes of Anosmia:

Chronic sinusitis – This inflammatory condition of the nasal passages and sinuses can cause swelling that disrupts airflow to the olfactory (smell) nerves that sense smell molecules. This is a potentially reversible cause of anosmia that can improve with medical treatment or surgery to improve airflow.

Nasal blockage – This cause is pretty straightforward. Collapse of the nostrils, septal deviation or turbinate enlargement can physically block air from reaching the top of the nasal cavity where the olfactory nerve lies. Medication can be helpful, but often a procedure is needed to open the nasal air passages to improve airflow.

Post viral anosmia – This can occur following a bad cold or flu. It is not clear why this happens, but it is thought to occur when the virus directly damages the olfactory nerves. This can be especially distressing since complete loss of smell can happen so quickly, often in 1 day. The recovery of smell is variable, with some studies showing that up to 75% of patients recover some smell up to several years following the loss.

Post traumatic anosmia – This can result from head injuries that directly shear the olfactory nerves as they enter the skull. This can result in complete loss of smell which is often not reversible.

Age related hyposmia – The aging process causes degradation of the olfactory nerves; this is why older adults often prefer stronger perfumes or stronger tasting foods. While this is often an unpleasant effect of getting older, it is important to get this evaluated since it may also be due to a reversible cause. It should also be noted that some studies have shown that abnormal loss of smell in older adults may be an early sign of dementia.

Treatment of anosmia

The treatment of loss of smell is highly variable and depends on the cause. If it is felt to be due to inflammation or blockage in the nasal cavity, anti inflammatory medications (oral or topical steroids) may be helpful as a first step in treatment. If the blockage cannot be relieved with medications, a procedure may be helpful.

If anosmia is thought to be due to nerve damage (such as post viral anosmia), there has been no 100% effective treatment to date. Many studies have been done on this topic and continue to be done. Several treatments have been shown to be somewhat helpful, but are far from being a cure. Due to lack of strong evidence, I do not recommend any long term oral medications for post viral anosmia.

Smell retraining therapy – the same way that physical therapy can improve muscle function after knee surgery, smell training has been shown to improve the sense of smell in patients with post viral anosmia.

Skip to content