Long-Term Smell Loss After COVID-19 More Common Than Believed, Study Finds
Table of Contents
- 1. Long-Term Smell Loss After COVID-19 More Common Than Believed, Study Finds
- 2. The Scope of the Problem
- 3. How COVID-19 impacts Smell
- 4. Beyond Sensory Perception: The wider Implications
- 5. Understanding Olfactory Dysfunction
- 6. Frequently Asked Questions About COVID-19 and Smell Loss
- 7. What are sustentacular cells and why are they important in understanding COVID-19 related smell loss?
- 8. Loss of Smell Uncovered in Millions Experiencing COVID-19: Unseen Effects of teh Virus
- 9. The Unique Neurological Impact of COVID-19 on Olfaction
- 10. How COVID-19 Causes Smell Loss: Beyond Nasal Blockage
- 11. The Spectrum of Smell Loss: From Anosmia to Parosmia
- 12. Long-Term Consequences of Smell Loss: More Than Just Food Taste
- 13. Smell Training: A Promising Recovery Strategy
- 14. Emerging Therapies and Research
New York, NY – October 18, 2025 – A concerning number of individuals continue to experience diminished olfactory function long after recovering from COVID-19, with many unaware of the extent of their impairment, according to research released today. The study, conducted by American Scientists, assessed the lasting impact of the SARS-CoV-2 virus on the sense of smell in a large cohort of individuals.
The Scope of the Problem
Researchers evaluated 2,956 people who had been infected with COVID-19 and compared them to a control group of 569 individuals who had not contracted the virus.The examination focused on olfactory ability an average of 671 days after initial testing. Findings indicate widespread, often unnoticed, smell dysfunction among those who experienced a COVID-19 infection.
Nearly 1,393 participants in the COVID-19 group reported a diminished sense of smell.Objective testing afterward validated that 80% of thes cases represented a genuine reduction or complete loss of smell – known as hyposmia or anosmia, respectively. Surprisingly, a further 1,563 individuals who *believed* their sense of smell remained intact were also found to have olfactory impairments in 66% of cases upon testing.
“Individuals who have had COVID-19 are at a significantly elevated risk for olfactory impairment, a medical issue that frequently enough goes unaddressed within the community,” stated Dr. Leora Horwitz, a co-author of the study from the NYU Grossman School of Medicine.
How COVID-19 impacts Smell
COVID-19 has become widely recognized as a leading cause of olfactory dysfunction since the start of the pandemic. The virus is understood to directly target cells and receptors within the nasal cavity, causing damage to the crucial nerve pathways responsible for transmitting olfactory signals to the brain. This disruption can lead to a partial or complete inability to detect smells.
Researchers have observed that many patients are not consciously aware of their diminished sense of smell because the virus can also affect the brain – specifically, the areas governing sensory perception. this can result in the brain being unable to register the impairment, or gradually adapting to the deficiency over time.
Did You Know? Loss of smell can impact more than just enjoyment of food; it can compromise safety by hindering the detection of dangers like gas leaks or spoiled food.
Beyond Sensory Perception: The wider Implications
The sense of smell plays a vital role in daily life, extending far beyond the simple pleasure of savoring aromas. It provides crucial warnings about potential hazards, such as gas leaks, fires, or the presence of spoiled food. Consequently, a subtle or unnoticed loss of smell can jeopardize safety and significantly diminish overall quality of life.
Growing scientific evidence suggests a strong correlation between olfactory loss and neurological disorders like Alzheimer’s disease. This raises concerns that COVID-19 may not only primarily impact the respiratory system but also have long-term repercussions for brain health and cognitive functions.
| Olfactory Condition | Definition | Prevalence in Post-COVID Patients (Study Findings) |
|---|---|---|
| Hyposmia | Reduced sense of smell | Reported by 1,393 patients; confirmed in 80% of those tested. |
| Anosmia | Complete loss of smell | included within the 80% confirmation rate for olfactory impairment. |
| Unrecognized Impairment | Impairment detected through testing despite patients reporting normal smell | 66% of 1,563 patients who believed their smell was normal. |
Researchers advocate for the incorporation of smell testing as a standard component of post-COVID-19 healthcare, especially for individuals who experienced any alterations in taste or smell during their initial infection.
“Even in the absence of immediate awareness,a loss of smell can profoundly impact both mental and physical well-being,” emphasizes Dr. Horwitz. “Early detection and intervention are crucial.”
This research underscores the need for continued investigation into the mechanisms driving olfactory recovery after viral infections, paving the way for the growth of more effective and targeted treatments in the future.
Do you think more awareness is needed regarding long-term COVID-19 symptoms? Are you concerned about the potential link between smell loss and neurological diseases?
Understanding Olfactory Dysfunction
Olfactory dysfunction, encompassing conditions like anosmia and hyposmia, extends beyond COVID-19. It can arise from a variety of causes,including upper respiratory infections (like the common cold),nasal polyps,sinus disease,head trauma,and neurodegenerative diseases. According to the American Academy of Otolaryngology – Head and Neck Surgery, approximately 5.6% of the global population experiences smell disorders.
Treatments for smell loss vary depending on the underlying cause. For COVID-19 related smell loss, olfactory training – a process of repeatedly sniffing specific scents – has shown promise in some cases. For other causes, treatments may involve medication, surgery, or lifestyle adjustments.
Frequently Asked Questions About COVID-19 and Smell Loss
- What is the primary way COVID-19 affects smell? COVID-19 impacts smell by damaging cells/receptors in the nasal cavity, disrupting the nerve pathways that transmit odor signals to the brain.
- Can I regain my sense of smell after COVID-19? Many people do recover their sense of smell, but recovery can be slow and incomplete. Olfactory training may help.
- Is smell loss from COVID-19 permanent? While some cases are permanent, many individuals experience gradual betterment over months or years.
- Why don’t some people realize they’ve lost their sense of smell? The brain can adapt to the loss, or the affected areas of the brain may prevent conscious awareness of the impairment.
- What should I do if I suspect I have lost my sense of smell after COVID-19? Consult a healthcare professional for evaluation and potential treatment options.
- Is there a link between smell loss and other health conditions? Yes, there is a growing body of research showing a link between smell loss and neurological conditions like Alzheimer’s and Parkinson’s Disease.
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Loss of Smell Uncovered in Millions Experiencing COVID-19: Unseen Effects of teh Virus
The Unique Neurological Impact of COVID-19 on Olfaction
The COVID-19 pandemic brought a host of symptoms to the forefront, but one ofen underestimated and surprisingly prevalent effect was anosmia – the loss of smell. Affecting a significant percentage of those infected, even those with mild cases, this symptom isn’t simply an inconvenience; it reveals a unique way the virus interacts with the human nervous system. Understanding this COVID-19 smell loss is crucial for both patient care and long-term health management. This article delves into the mechanisms behind this phenomenon,its lasting consequences,and what can be done to address it.
How COVID-19 Causes Smell Loss: Beyond Nasal Blockage
Initially, it was assumed that smell loss during COVID-19 was due to nasal congestion, similar to a common cold. However, research quickly revealed a more complex picture. The SARS-CoV-2 virus doesn’t primarily damage the olfactory receptors directly. Instead, it targets supporting cells in the olfactory epithelium – the tissue lining the nasal cavity responsible for detecting odors.
Here’s a breakdown of the process:
- ACE2 Receptor expression: These supporting cells, particularly sustentacular cells, express high levels of the ACE2 receptor, which the virus uses to enter cells.
- Inflammation & Disruption: Viral infection triggers inflammation and disrupts the normal function of these supporting cells.
- Olfactory Neuron Impact: While olfactory neurons themselves aren’t typically infected, the disruption of support cells impairs thier ability to function correctly, leading to hyposmia (reduced sense of smell) or anosmia.
- Central Nervous System Involvement: Emerging evidence suggests the virus can also indirectly affect the olfactory bulb, the brain region responsible for processing smells, contributing to prolonged smell dysfunction.
This differs considerably from smell loss caused by a cold or allergies, where nasal congestion physically blocks odor molecules from reaching the receptors. COVID-related smell loss is often described as a sudden, complete loss of smell, even with a clear nasal passage.
The Spectrum of Smell Loss: From Anosmia to Parosmia
The experience of smell loss varies widely among individuals. It’s not always a simple “on/off” switch.Here’s a look at the different types:
* Anosmia: Complete loss of smell.
* Hyposmia: Reduced ability to smell.
* Parosmia: Distorted sense of smell – familiar odors are perceived differently, often as unpleasant or metallic. This is a particularly distressing symptom for many.
* Phantosmia: Perception of smells that aren’t actually present (olfactory hallucinations).
The duration of these symptoms also varies. While many experience a return of smell within weeks, a significant proportion – estimated between 10-30% – report persistent long COVID smell loss lasting months or even years.
Long-Term Consequences of Smell Loss: More Than Just Food Taste
The impact of prolonged anosmia extends far beyond the inability to enjoy food. smell is intricately linked to several vital functions:
* Safety: Detecting dangers like gas leaks, smoke, or spoiled food.
* Nutrition: Smell contributes significantly to the perception of flavor, potentially leading to decreased appetite and nutritional deficiencies.
* Mental Health: Loss of smell is strongly associated with depression, anxiety, and a reduced quality of life. The emotional connection to smells – memories triggered by scent – is also lost.
* Social Impact: Difficulty enjoying social situations involving food or experiencing the surroundings fully.
Smell Training: A Promising Recovery Strategy
For many experiencing post-COVID anosmia, smell training (olfactory training) has emerged as a promising recovery strategy. This involves repeatedly sniffing a set of four distinct scents – typically rose, lemon, clove, and eucalyptus – twice daily for several months.
Here’s how it works:
- Neuroplasticity: Smell training aims to stimulate the olfactory neurons and promote neuroplasticity – the brain’s ability to reorganize itself by forming new neural connections.
- Consistent Exposure: Repeated exposure to these scents helps to “retrain” the olfactory system and potentially restore the ability to detect and identify odors.
- Early Intervention: Starting smell training quickly after the onset of smell loss appears to yield better results.
While not a guaranteed cure,studies have shown that smell training can significantly improve olfactory function in a significant number of patients.
Emerging Therapies and Research
Beyond smell training, researchers are exploring other potential therapies for COVID-19-related smell loss:
* Intranasal Steroids: To reduce inflammation in the nasal passages.
* Platelet-Rich Plasma (PRP) Therapy: Involving injecting concentrated platelets into the nasal cavity to promote tissue repair. (Still experimental)
* Olfactory Stem Cell Therapy: A more advanced approach aiming to regenerate damaged olfactory neurons. (Currently in early stages of research)
Ongoing research is focused on understanding the long-term effects of
