This doesn’t always result in a complete loss of smell. Those affected may be able to still detect certain odours, although the degree of this ability, and the odours themselves, varies from person to person. What can compound the problem is the fact that PVOL patients are likely to be affected by parosmia, distortions of the sense of smell. Again, the degree of parosmia varies from patient to patient.

Post-viral olfactory loss doesn’t always manifest itself suddenly, but can develop gradually over time. Many of us will get the common cold or a similar virus at least once or twice a year or more.  Some PVOL patients may experience a slight loss of smell following each cold, until after a particular bout they realise they cannot smell, without having noticed that it was deteriorating.

Post-viral olfactory loss tends to be more common in females between the ages of 40 and 70, although the reasons for this aren’t clear.

As we’ve said above, the mechanism by which viruses cause a loss of smell is not yet understood, which makes treatment difficult.  However, there are a number of positives.

Studies have shown that spontaneous recovery is more common in patients who have suffered postviral olfactory loss than with any other causation.  Any recovery is probably more likely to be partial than complete, however, and it isn’t possible to predict how long it will take for things to start to improve. That said, one study published in 2014 found that over 80% of participants experienced subjective improvement in olfactory ability one year after initial loss.¹

What can be a valuable aid to those experiencing a post-viral smell disorder is smell training.  Several research studies have shown that smell training can be particularly beneficial to people who have suffered post-viral olfactory loss.²  It is thought that actively sniffing various odours such as the essential oils detailed on our smell training page can help the olfactory receptor cells regenerate and become active again.

PVOL and Parosmia

A major challenge for many people affected by post-viral olfactory loss is that parosmia, a distorted sense of smell, can be common experience with this causation.  These distorted smells are almost universally unpleasant, and can range in severity from being very mild to very severe.  This can pose a challenge when undertaking smell training, and have a negative effect on people’s everyday lives. You can find out more on our page about Parosmia and Phantosmia