Coronavirus might have hit the UK before we first thought and it's possible you've already had it.

And there are eight signs that you could have had coronavirus Covid-19 a month before it was previously thought to have arrived in Britain

Research carried out by Oxford University's Evolutionary Ecology of Infectious Disease group suggests that Covid-19 may have reached the UK by mid-January at the latest.

The scenario is one of the several the researchers presented as possible, and goes against previously understood death rates, reported The Mirror.

In the non-peer reviewed study they suggest that the coronavirus, like many emerging infections, may have spread invisibly for a month before its effects became clear at the end of February.

If the Oxford researchers are right, then as much as half of the country's population may already have been infected.

Eye Infections

New research has indicated that eye infection such as conjunctivitis may be a symptom of Covid-19.

The College of Optometrists said: "It is recognised that any upper respiratory tract infection may result in viral conjunctivitis as a secondary complication, and this is also the case with Covid-19.

"However, it is unlikely that a person would present with viral conjunctivitis secondary to Covid-19 without other symptoms of fever or a continuous cough as conjunctivitis seems to be a late feature where is has occurred."

A dry cough

Breathing in coronavirus test slammed by experts
Breathing in coronavirus test slammed by experts

Many people experienced symptoms linked to Covid-19 in the weeks following the New Year.

Perhaps the most recognisable of the Covid-19 symptoms is the dry cough, given how different it can sound compared to a typical cough.

The cough is generally new for you - or different if you generally have a smoker's cough - and persistent.

More often than not it will last for at least half a day.

Mental Fatigue

Women wearing masks to protect against coronavirus

Although this has not been officially chalked up as a symptom, Covid-19 sufferers have reported experiencing mental fatigue.

Thea Jourdan told The Daily Mail that she first thought she may have been infected when she got a tickle in her throat and a headache.

The mum-of-three then began to experience brain fog.

"Initially I felt exhausted, as if I was dragging myself through treacle and had no choice but to go to my bed. I had no meaningful cough and I wasn’t running a fever," the Hampshire woman told the publication.

"But I had a peculiar sensation of something settling deep within my lungs, almost like breathing in talcum powder."

A high temperature

Coronavirus may mean you've got a prolonged period at home with nothing to do
Coronavirus may mean you've got a prolonged period at home with nothing to do

Although numbers vary for different people, a rise in body temperature generally counts as a fever once it reaches 37.7C (100F).

You can tell you have a fever if you feel hot to the touch on your chest or back.

It's difficult to catch your breath

If your chest starts to feel tight or you cannot breath, you may have caught the coronavirus.

Most young people or those without pre-existing health conditions are unlikely to experience this symptom.

Dyspnea - the term for when someone has difficulty breathing - may be coupled with a tightness in the chest, rapid breathing and heart palpitations.

Loss of smell and taste

A woman wears a mask in Newcastle, near to the city's Royal Victoria Infirmary
A woman wears a mask in Newcastle, near to the city's Royal Victoria Infirmary

Over the weekend the British Association of Otorhinolaryngology warned that losing your sense of smell and taste may mean you have Covid-19.

The ear, nose and throat specialist recommended anyone with such symptoms self-isolate immediatley.

It has been suggested that the phenomena may be caused by the coronavirus killing cells in the nose and throat.

"Evidence from other countries that the entry point for the coronavirus is often in the eyes, nose and throat areas," the Association said in a statement.

"We have also identified a new symptom (loss of sense of smell and taste) that may mean that people without other symptoms but with just the loss of this sense may have to self-isolate - again to reduce the spread of the virus."

Tummy ache

As with a loss of appetite, enduring a tummy ache may easily be passed off as a sign of something more innocuous.

However, a newly published study by the American Journal of Gastroenterology links tummy problems to Covid-19.

They found that 48.5% of 204 people who have been infected by the coronavirus in China's Hubei province had digestive symptoms such as diarrhoea.

Physical fatigue

Another common symptom of Covid-19, as well as cold, flu and many viruses in general, is feeling tired or fatigued.

Being told to rest is common when you’re ill, but feeling tired and not being able to sleep due to coughs and difficulty breathing, can make things all the more difficult.

Jaimuay Sae-ung, 73, was the first Thai national to contract coronavirus in December last year.

Despite having underlying health conditions, including a heart problem, Jaimuay survived the illness after doctors isolated her at a hospital in Thailand for treatment.

"I only knew (I had coronavirus) after I came to the hospital," the mother of seven told Sky News.

"I felt a bit sad, a bit shocked, tired and fatigued and I couldn't eat."

It is important to note that you may have had one or several of these symptoms but have not had Covid-19.