Your Sense of Smell Can Return After COVID—But It Can Get Weird

Key TakeawaysThe loss of the sense of smell, also called anosmia, is a common symptom of COVID-19. In fact, it happens more often thanfeveror respiratory symptoms.Researchers have found that COVID, like otherviral infections, can cause the loss of the sense of smell. It’s related to how the virus attacks the cells in the back of the nose.A lost sense of smell may come back slowly after an illness. But for some people, it may not return completely—or at all. When the sense of smell does come back, things that should smell good smell might smell bad at first. This condition is called parosmia.

Key Takeaways

The loss of the sense of smell, also called anosmia, is a common symptom of COVID-19. In fact, it happens more often thanfeveror respiratory symptoms.Researchers have found that COVID, like otherviral infections, can cause the loss of the sense of smell. It’s related to how the virus attacks the cells in the back of the nose.A lost sense of smell may come back slowly after an illness. But for some people, it may not return completely—or at all. When the sense of smell does come back, things that should smell good smell might smell bad at first. This condition is called parosmia.

One sign of a COVID-19 infection is the loss of the sense of smell, also known as anosmia. It is the main neurological symptom of COVID. And it affects about 90 percent of patients with the virus.Experts say that loss of smell might be a better sign of COVID infection than othersymptoms of the illness.

This article will discuss what it means if someone with COVID or another viral infection loses their sense of smell. It will talk about whether the sense of smell comes back after you have COVID. It will also talk about whether your sense of smell will be the same as it was before.

Loss of Sense of Smell May Be Best Sign of COVID-19, Studies Find

Viruses and Sense of Smell

Eric Holbrook, MDis an associate professor of otolaryngology and head andneck surgeryat Harvard Medical School. Dr. Holbrook is also division director for rhinology at Massachusetts Eye and Ear at Massachusetts General Hospital. Dr. Holbrook tells Verywell that other viruses besides COVID can cause anosmia.

“Post-viral smell loss was a known entity,” says Holbrook. “We were unable to directly identify what viruses caused it mostly because these patients would come in long after the acute symptoms, and so it’s very hard to detect what virus actually caused it.“

People may lose their sense of smell when they have stuffed up sinuses from acoldor theflu. While it can be temporary, some people will notice that their sense of smell has not come back after thenasal congestionclears.

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Holbrook specializes in treating disorders of the senses of smell andtasteand says that Around 40 percent of the patients that would come to Holbrook had a history of having a cold, and then losing their sense of smell. It’s also possible for people to suddenly lose their sense of smell after ahead injury.

Coronaviruses other than SARS-CoV-2 can also cause the loss of the sense of smell. Holbrook says that anosmia was reported with some cases of the coronavirus that caused the outbreak of severe acute respiratory syndrome (SARS) in 2003 and 2004. But the symptom was “not nearly as prevalent as it is with COVID-19.”

Researchers in Europe found that 86 percent of a group of 417 patients with mild-to-moderate COVID-19 lost their sense of smell. A second, larger, study found that 87 percent of 2,013 patients with mild-to-moderate COVID-19 lost their sense of smell as well.

“If you have a normal sense of smell, and you suddenly lose it, you really notice it,” said Holbrook. “The combination of smell and taste is what gives you a sense of flavor in food.”

Loss of Taste, Smell in COVID-19 Might Last Up to 5 Months

Some people with COVID-related anosmia recover within a few weeks. But many people may take longer to recover. One study found that about 95 percent of people recovered from COVID-related anosmia within six months.

What Causes Loss of Smell?

The structures that make up the sense of smell are located in the roof of the nasal cavity, They are specifically located behind the nose and just in front of thebrain. The olfactory sensory neurons detect molecules in the air that are connected to the substances around us. These are then connected directly to the brain. Odors reach the neurons both through the nostrils and the mouth.

Eric Holbrook, MDIf you have a normal sense of smell, and you suddenly lose it, you really notice it. The combination of smell andtasteis what gives you a sense of flavor in food.

Eric Holbrook, MD

If you have a normal sense of smell, and you suddenly lose it, you really notice it. The combination of smell andtasteis what gives you a sense of flavor in food.

When the coronavirus started affecting patients’ sense of smell, the worry was that the neurons were affected. This suggested that other neurological problems could be occurring.

Datta and his colleagues found that the sensory neurons do not have a receptor protein called ACE2. This is the protein that the SARS-CoV-2 virus uses to break into human cells.But the cells that provide support to the neurons do have the protein. This is why the virus can attack them.

Holbrook said that the research suggested that damage to the sense of smell and the association of having smell loss with COVID-19 is probably related to the inflammation that occurs around the sensory neurons. But it does not necessarily directly infect them to cause damage.

‘Smell Training’ Could Help People Who Lost Their Sense of Smell From COVID-19

Why Smells Might Be Weird After COVID

Since the sensory neurons are not affected, the lost sense of smell that can occur with COVID is unlikely to be permanent. Theolfactory sensoryneurons and other cells can regrow. This means that, unlike vision or hearing loss, you can get back your sense of smell.

Recovery of the sense of smell doesn’t always happen. But when it does happen, there can be missteps along the way. The nerves grow slowly and have to reconnect to the brain. And those new connections may have a shakedown period during which they do not function well.

Holbrook said thatparosmiacan also happen. This is where what you experience as a smell does not match the actual odor. For example, a sniff of a rose ends up being experienced as a whiff of skunk. Curiously, the wrong sensation will usually be a bad one rather than a good one. A rose might smell like a skunk but not the reverse.

Summary

If you have had COVID and have lost your sense of smell, know that this symptom is very common. Some people regain the sense within a few weeks of recovering. But it can take longer for other people. As the sense returns, smells might be experienced in unusual ways for a while. In some cases, the loss of sense of smell is permanent.

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit ourcoronavirus news page.

3 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Saussez S, Lechien JR, Hopkins C.Anosmia: an evolution of our understanding of its importance in COVID-19 and what questions remain to be answered.Eur Arch Otorhinolaryngol. 2021;278(7):2187-2191. doi:10.1007/s00405-020-06285-0Lechien JR, Chiesa‐Estomba CM, Beckers E, et al.Prevalence and 6‐month recovery of olfactory dysfunction: a multicentre study of 1363 COVID‐19 patients.J Intern Med. 2021;290(2):451-461. doi:10.1111/joim.13209Brann DH, Tsukahara T, Weinreb C, et al.Non-neuronal expression of SARS-CoV-2 entry genes in the olfactory system suggests mechanisms underlying COVID-19-associated anosmia.Sci Adv. 2020;6(31):eabc5801. doi:10.1126/sciadv.abc5801Additional ReadingLechien JR, Chiesa-Estomba CM, De Siati DR, et al.Olfactory and gustatory dysfunctions as a clinical presentation of mild-to-moderate forms of the coronavirus disease (COVID-19): a multicenter european study.Eur Arch Otorhinolaryngol. 2020;277(8):2251-2261. doi:10.1007/s00405-020-05965-1Lechien JR, Chiesa-Estomba CM, Hans S, Barillari MR, Jouffe L, Saussez S.Loss of smell and taste in 2013 european patients with mild to moderate COVID-19.Ann Intern Med. 2020;173(8):672-675. doi:10.7326/M20-2428

3 Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Saussez S, Lechien JR, Hopkins C.Anosmia: an evolution of our understanding of its importance in COVID-19 and what questions remain to be answered.Eur Arch Otorhinolaryngol. 2021;278(7):2187-2191. doi:10.1007/s00405-020-06285-0Lechien JR, Chiesa‐Estomba CM, Beckers E, et al.Prevalence and 6‐month recovery of olfactory dysfunction: a multicentre study of 1363 COVID‐19 patients.J Intern Med. 2021;290(2):451-461. doi:10.1111/joim.13209Brann DH, Tsukahara T, Weinreb C, et al.Non-neuronal expression of SARS-CoV-2 entry genes in the olfactory system suggests mechanisms underlying COVID-19-associated anosmia.Sci Adv. 2020;6(31):eabc5801. doi:10.1126/sciadv.abc5801Additional ReadingLechien JR, Chiesa-Estomba CM, De Siati DR, et al.Olfactory and gustatory dysfunctions as a clinical presentation of mild-to-moderate forms of the coronavirus disease (COVID-19): a multicenter european study.Eur Arch Otorhinolaryngol. 2020;277(8):2251-2261. doi:10.1007/s00405-020-05965-1Lechien JR, Chiesa-Estomba CM, Hans S, Barillari MR, Jouffe L, Saussez S.Loss of smell and taste in 2013 european patients with mild to moderate COVID-19.Ann Intern Med. 2020;173(8):672-675. doi:10.7326/M20-2428

Saussez S, Lechien JR, Hopkins C.Anosmia: an evolution of our understanding of its importance in COVID-19 and what questions remain to be answered.Eur Arch Otorhinolaryngol. 2021;278(7):2187-2191. doi:10.1007/s00405-020-06285-0Lechien JR, Chiesa‐Estomba CM, Beckers E, et al.Prevalence and 6‐month recovery of olfactory dysfunction: a multicentre study of 1363 COVID‐19 patients.J Intern Med. 2021;290(2):451-461. doi:10.1111/joim.13209Brann DH, Tsukahara T, Weinreb C, et al.Non-neuronal expression of SARS-CoV-2 entry genes in the olfactory system suggests mechanisms underlying COVID-19-associated anosmia.Sci Adv. 2020;6(31):eabc5801. doi:10.1126/sciadv.abc5801

Lechien JR, Chiesa‐Estomba CM, Beckers E, et al.Prevalence and 6‐month recovery of olfactory dysfunction: a multicentre study of 1363 COVID‐19 patients.J Intern Med. 2021;290(2):451-461. doi:10.1111/joim.13209

Brann DH, Tsukahara T, Weinreb C, et al.Non-neuronal expression of SARS-CoV-2 entry genes in the olfactory system suggests mechanisms underlying COVID-19-associated anosmia.Sci Adv. 2020;6(31):eabc5801. doi:10.1126/sciadv.abc5801

Lechien JR, Chiesa-Estomba CM, De Siati DR, et al.Olfactory and gustatory dysfunctions as a clinical presentation of mild-to-moderate forms of the coronavirus disease (COVID-19): a multicenter european study.Eur Arch Otorhinolaryngol. 2020;277(8):2251-2261. doi:10.1007/s00405-020-05965-1Lechien JR, Chiesa-Estomba CM, Hans S, Barillari MR, Jouffe L, Saussez S.Loss of smell and taste in 2013 european patients with mild to moderate COVID-19.Ann Intern Med. 2020;173(8):672-675. doi:10.7326/M20-2428

Lechien JR, Chiesa-Estomba CM, Hans S, Barillari MR, Jouffe L, Saussez S.Loss of smell and taste in 2013 european patients with mild to moderate COVID-19.Ann Intern Med. 2020;173(8):672-675. doi:10.7326/M20-2428

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Key Takeaways#

Viruses and Sense of Smell#

What Causes Loss of Smell?#

Eric Holbrook, MD#

Why Smells Might Be Weird After COVID#

Summary#