The inability to smell (anosmia) or a reduced sense of smell (hyposmia) significantly affects daily life. Smell is connected to the perception of flavor, making eating less enjoyable, and it is a powerful warning system for hazards like smoke or spoiled food. Olfaction is a complex process involving specialized cells in the nose that send messages to the brain, which then identifies the scent. Fortunately, for many people, methods exist to promote the recovery of this sense.
Identifying the Underlying Cause
The path toward restoring your sense of smell depends entirely on an accurate diagnosis of the underlying cause, which requires a medical consultation. Causes of smell loss can be broadly grouped into three categories, each requiring a different treatment approach. One common group is Conductive or Obstructive loss, where a physical blockage prevents odor molecules from reaching the olfactory receptors. This type of loss is often caused by growths like nasal polyps, severe congestion, or structural issues such as a deviated septum.
Another major category is Sensorineural loss, which involves damage to the olfactory nerves or the part of the brain that processes smell. This frequently occurs following viral infections, including influenza and COVID-19, or after a head trauma. The third group is Inflammatory loss, typically seen in chronic rhinosinusitis, where persistent inflammation and swelling in the nasal passages and sinuses damage the olfactory mucosa. Determining the specific cause is the necessary first step, as prescription treatments are ineffective for nerve damage, while olfactory training is less helpful for physical blockages.
The Practice of Olfactory Training
Olfactory training is a safe, non-pharmacological method well-suited for sensorineural loss, such as that caused by a viral infection or head injury. The technique relies on the brain’s ability to reorganize and adapt (neuroplasticity), strengthening the connections between the nose and the brain. Consistent exposure to strong odors encourages the regeneration and functional improvement of damaged olfactory receptor neurons.
The standard protocol involves selecting four distinct scent categories: a floral (like rose), a fruity (like lemon), a resinous or spicy (like clove), and a gourmand or eucalyptus scent. These scents should be presented at a high concentration, often in the form of concentrated essential oils. The training requires individuals to sniff each of the four chosen odors sequentially for approximately 15 to 30 seconds.
This process must be performed twice daily, with a conscious effort to recall the memory of the smell. To maximize the training effect, continue the practice for a minimum of three to six months; a duration of 24 weeks or longer may yield superior results. Some protocols suggest rotating the four scents every three months to introduce new stimuli.
Medical and Surgical Treatment Options
Treatments involving a physician are generally focused on resolving inflammatory or obstructive causes of smell loss. For cases involving chronic inflammation, such as chronic rhinosinusitis, topical treatments are often the first line of defense. Intranasal corticosteroid sprays or steroid rinses work to reduce swelling and inflammation in the nasal lining, allowing odor molecules better access to the olfactory receptors.
If inflammation is severe and unresponsive to topical medication, a short course of oral corticosteroids may be prescribed. For bacterial infections contributing to the issue, antibiotics may be used to eliminate the infection and reduce inflammation. These medical interventions aim to clear the physical pathway necessary for smell.
When smell loss is due to a physical obstruction, such as large nasal polyps or a deviated septum, surgical intervention may be necessary. Procedures like endoscopic sinus surgery can remove tissue growths or correct structural abnormalities blocking airflow to the olfactory region. Surgery often provides the most direct path to recovery when the underlying cause is mechanical.
Safety Adjustments and When to Consult a Specialist
While pursuing treatment, implement practical safety measures to mitigate risks associated with a compromised sense of smell. Since the ability to detect hazards like smoke or gas is impaired, ensure that smoke detectors and carbon monoxide detectors are functional and properly installed. Furthermore, rely on visual cues and check expiration dates to avoid consuming spoiled food.
A consultation with a specialist, such as an otolaryngologist, is warranted if smell loss is persistent or does not resolve after a common cold or allergy subsides. Immediate professional attention is necessary for “red flag” symptoms that may indicate a more serious underlying issue. These include a sudden, unexplained loss of smell, loss on only one side of the nose, or loss accompanied by neurological symptoms like vision changes, severe headache, or dizziness.