A study found people experienced prolonged symptoms after having respiratory infections such as colds, flu and pneumonia - in the same way they might after getting COVID.

Common symptoms of a "long cold" include coughing, stomach pain and diarrhoea lasting for more than a month.

Long COVID patients were more likely to suffer lightheadedness, dizziness and problems with taste and smell.

They also experienced heart palpitations, sweating and hair loss.

Some symptoms overlapped, including breathlessness and fatigue.

Researchers at the Queen Mary University of London analysed data from 10,171 adults in the UK for the study, which has been published the The Lancet's EClinicalMedicine journal.

The findings suggested "there may be long-lasting health impacts following non-COVID acute respiratory infections such as colds, influenza or pneumonia, that are currently going unrecognised", they said.

However, more research is needed to establish whether the symptoms can last for the same or a similar duration to long COVID - and why some people suffer more than others.

Having a more serious illness can increase the chances of having long-term health issues, the study found.

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The data was collected as part of the university's "Covidence UK" national study of COVID-19, which was launched in 2020.

Chief investigator, professor Adrian Martineau, said the findings could resonate with people who have struggled with long-term symptoms after having a respiratory infection, despite testing negative for COVID using a nose or throat swab.

He highlighted the importance of ongoing research to help "get to the root of why some people experience more prolonged symptoms than others".

"Ultimately this could help us to identify the most appropriate form of treatment and care for affected people," he added.

Lead author Giulia Vivaldi from Queen Mary University of London said: "Our findings shine a light not only on the impact of long COVID on people's lives, but also other respiratory infections.

"A lack of awareness - or even the lack of a common term - prevents both reporting and diagnosis of these conditions.

"As research into long COVID continues, we need to take the opportunity to investigate and consider the lasting effects of other acute respiratory infections.

"These 'long' infections are so difficult to diagnose and treat primarily because of a lack of diagnostic tests and there being so many possible symptoms.

"There have been more than 200 (symptoms) investigated for long COVID alone."

The study looked at people's symptoms after their initial infection, using standardised questionnaires.

The longest time from initial infection to reports of ongoing symptoms was 37 weeks for non-COVID infections and 64 weeks for people with COVID.

Post-viral illness is not a new phenomenon, Ms Vivaldi added, but existing research has focused primarily on people who survived a severe infection, often having been hospitalised.

Long COVID has shown people can be plagued by lingering symptoms irrespective of the severity of their infection, she said.

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Around 1.9m people in the UK are thought to be living with long COVID.

A study in September found a third of long COVID patients sustained damage to multiple organs five months after infection.

Scans of patients who received hospital treatment for the virus showed higher rates of damage to the lungs, brain and kidneys.

Sky News' technology correspondent Rowland Manthorpe documented his struggle after suffering long COVID for more than 18 months.

He said the condition had 'ruined his life', leaving him with crippling fatigue and brain fog.

Research in January found long COVID sufferers who had a mild bout of the virus should expect their symptoms to resolve within a year.

An experimental drug offered the hope of significantly reducing fatigue in people with long COVID.