The experience of having a weird smell in your nose after COVID-19 is known as parosmia, a medical condition characterized by a distorted sense of smell. For many who recover from COVID-19, their sense of smell either disappears (anosmia) or is significantly reduced (hyposmia) before returning distorted. A related condition, phantosmia, causes a person to smell things that aren't actually present, like smoke or chemicals. These post-viral olfactory dysfunctions are a key feature of 'long COVID' and can be both frustrating and isolating.
The science behind the distorted smells
Unlike a regular cold that blocks the nose with congestion, COVID-19 affects the olfactory system on a neurological level. The SARS-CoV-2 virus directly impacts the supportive cells in the nasal tissue that nurture the olfactory sensory neurons—the nerve cells responsible for detecting smells. Although the virus does not directly infect the neurons, the damage to the supporting cells triggers an inflammatory response. This causes the neurons to malfunction or become damaged, leading to the temporary loss of smell experienced during the acute phase of the infection.
How nerve regeneration causes parosmia
As the body recovers, the olfactory neurons regenerate. However, this process is not always perfect, and the new nerve connections can be 'miswired,' sending incorrect signals to the brain's olfactory center. The brain, receiving these scrambled signals, misinterprets once-familiar scents, causing them to smell unpleasant or bizarre. This explains why something like coffee or meat can suddenly smell like gasoline, sewage, or something rotten.
Brain changes in long COVID patients
Furthermore, research indicates that the COVID-19 virus can have more far-reaching effects, potentially affecting the smell center of the brain itself. Studies comparing MRI scans before and after SARS-CoV-2 infection have shown changes in brain structure in regions critical for odor discrimination and memory. This interplay between peripheral nerve regeneration and central brain pathway changes likely contributes to the persistence of smell distortions in some individuals.
Common trigger smells and how to cope
Many people with post-COVID parosmia report specific odors that become unbearable. The intense aversions can turn daily activities like cooking and eating into a deeply unpleasant experience.
Common Parosmia Triggers:
- Cooking onions or garlic
- Roasted or fried meat
- Coffee
- Eggs
- Citrus fruits
- Toothpaste
These triggers can cause nausea and impact nutrition, with some people even resorting to bland foods or smoothies to avoid the repulsive smells. To manage these symptoms, individuals often learn to avoid their specific trigger foods and eat at a cooler temperature, as heat can amplify the smell.
The recovery timeline and treatment options
For most people, the distortion of smell is temporary and improves over time, but the timeline can vary significantly. While some see improvement within a few months, others report persistent issues for a year or longer.
| Comparison of Recovery Approaches | Feature | Olfactory Training | Intranasal Steroids | Neuromodulating Medication |
|---|---|---|---|---|
| Method | Involves smelling a series of strong scents (rose, lemon, clove, eucalyptus) twice daily for several months. | Nasal spray therapies (fluticasone, mometasone) to reduce inflammation. | Prescription drugs like gabapentin or amitriptyline, used in severe cases to alter nerve signals. | |
| Effectiveness | Considered one of the most effective, non-invasive treatments. Results often seen over weeks or months. | May improve smell in 10-25% of patients, but effectiveness varies. | Limited research shows potential benefits for severe symptoms, but side effects are a concern. | |
| Side Effects | None typically reported, considered low-risk. | Low-risk, but potential for local irritation. | Potential for significant side effects, requiring careful medical supervision. | |
| Patient Involvement | Requires consistent, long-term commitment from the patient. | Minimal patient effort required after initial training. | Requires strict adherence to prescription schedule and monitoring. |
The road to recovery
Most importantly, patience is key. The olfactory nerves can regenerate, and many people experience a slow but steady recovery, even if it takes years. Regular olfactory training, as detailed above, can help retrain the nervous system and is widely recommended. Some find support from patient communities like AbScent to be helpful for navigating the psychological and emotional toll. If symptoms persist or cause significant distress, consulting an ear, nose, and throat (ENT) specialist can help rule out other causes and offer further guidance. For those struggling, resources and support systems are available to help manage the invisible struggle of post-COVID olfactory dysfunction. For additional support and information, the non-profit organization Fifth Sense provides valuable resources for those with smell and taste disorders.
Conclusion: Navigating the new normal of smell
Living with a distorted sense of smell after COVID-19 can be deeply unsettling, affecting everything from daily meals to personal hygiene. Understanding that this phenomenon, known as parosmia, is a result of nerve damage and imperfect regeneration is the first step toward managing it. While the recovery timeline is different for everyone, consistent olfactory training offers a proactive way to stimulate healing. Remember to prioritize safety by checking expiration dates and having working smoke alarms, and consider seeking professional medical and emotional support when needed. The journey can be long, but hope for recovery remains, and with time and persistence, your sense of smell may continue to improve.
