A high temperature, continuous cough and a loss to your sense of smell are main symptoms of coronavirus.
And typically people who have had the virus will display some semblance of immunity for months after.
But how do you know if you've had Covid-19 without testing positive or taking an antibody test?
Well, there are eight tell-tale signs.
These symptoms and signs could show up months after your battle with the virus, reports Birmingham Live.
Cough - with a difference
Persistent coughs are a well-known sign that you may be infected with coronavirus.
Typically, these sound different to the usual cough you'll get - and they even differ from 'smokers cough' too.
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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.
"However, it is unlikely that a person would present with viral conjunctivitis secondary to Covid without other symptoms of fever or a continuous cough as conjunctivitis seems to be a late feature where is has occurred."
Dyspnea - the term for when someone has difficulty breathing - may be coupled with a tightness in the chest, rapid breathing and heart palpitations.
A newly published study by the American Journal of Gastroenterology links stomach problems to Covid.
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.
The big issue affecting Covid sufferers months on appears to be a fatigue and tiredness which is incredibly difficult to overcome for those who have had Covid.
Brain fog has plagued Long Covid sufferers, with people detailing accounts of experiencing it for months after battling the bug.
Hot to touch
A high temperature is considered a fever when it reaches 37.7C (100F).
Sudden loss of taste or smell
The three official symptoms of Covid-19 listed by the NHS include a persistent, hard-to-shift cough, which develops quickly.
Others include a sudden loss of taste or smell, which was the third official symptom discovered by the likes of the NHS and WHO.
Other signs include a fever or high temperature.