Smell loss is one of the most prevalent symptoms of long COVID, according to a new study.

According to the research, it reveals that almost a third of long COVID patients suffer persistent smell loss, with almost a fifth experiencing loss of taste.

The team from the University of East Anglia (UEA), UK, investigated the prevalence of long COVID, particularly ear, nose and throat-related symptoms such as smell loss and parosmia, where people experience strange and often unpleasant smell distortions.

The findings have been published in the journal International Forum of Allergy and Rhinology.

"Long COVID is a complex condition that develops during or after having COVID, and it is classified as such when symptoms continue for more than 12 weeks," said lead researcher Carl Philpott, UEA.

"Symptoms include headache, myalgia, fatigue and loss of taste and smell. Parosmia can persist for months after the initial infection, alongside brain fog and memory loss.

"We wanted to find out more about the prevalence of long COVID, and particularly ear, nose and throat related symptoms such as smell loss and parosmia," said Philpott.

The team looked at results from the UK Coronavirus Infection Survey and analysed information from over 3,60,000 people in March 2022.

A total of 10,431 participants identified as suffering from long COVID, and were asked about the presence of 23 individual symptoms and the impact of the condition on their day-to-day activities, the study said.

Self-reported long COVID was defined as symptoms persisting for more than four weeks after the first suspected coronavirus infection but not explained by another condition.

"We found that almost three percent of the participants self-identified as having long COVID, and if we scale this up to reflect the UK population, it would equate to around 1.8 million people," said Philpott.

"We found that fatigue was the most common symptom, whilst ENT-related symptoms included a loss of smell and taste, vertigo, shortness of breath, wheezing and a sore throat.

"Almost a third of self-reported long COVID patients were suffering persistent smell loss, and almost a fifth were still experiencing loss of taste.

"This is really significant because we know that loss of smell and taste really impacts people's lives. Our previous research has shown that people who have lost their sense of smell also report high rates of depression, anxiety, isolation and relationship difficulties.

"It can disrupt almost every aspect of life - from everyday concerns about personal hygiene to a loss of sexual intimacy and the break-down of personal relationships.

"Christmas in particular can be a difficult time. So much of our celebration is based around festive smells and tastes - from the smell of the tree and mulled wine to tasting Christmas dinner, mince pies and chocolates.

"Long COVID is a growing problem in the UK and we need to focus resources on supporting people with loss of smell and taste after COVID infection," said Philpott.

This research was led by the University of East Anglia in collaboration with the charity Fifth Sense which represents those with smell and taste disorders.