Some studies show that up to 40% of people with COVID-19 are asymptomatic or have very mild symptoms. That means they don't feel bad, but the virus can affect the body, which is why proper treatment is required. Lung X-rays of asymptomatic people showed lung damage typical of COVID-19 infection.

Moreso, even if some people don't have the classic signs and symptoms of the virus or are asymptomatic, they can still be carriers and therefore contagious to others.

The symptoms of COVID-19 infection can be similar to colds but there are some differences such as the longer duration of the infectious episode, around 2 weeks or even longer. And unlike a cold, the COVID-19 virus can cause fever.

The feeling of fatigue is a frequent symptom of COVID-19 infection and usually does not improve with sleep. The feeling of fatigue may return after a few days and sometimes after a few weeks or may persist for weeks after the end of the infectious episode.

A dry cough that lasts for a long time could be a symptom of COVID-19. Coughing from COVID-19 infection starts easily, worsens after 5-7 days and can have very intense episodes during the 2 weeks that lasts on average an episode infected with COVID-19.

The sensation of heavy breathing or difficulty breathing, also called breathlessness, is commonly associated with infection with COVID-19. Heavy breathing is usually also associated with respiratory symptoms such as nasal congestion.

The COVID-19 virus can affect the heart, more precisely it can cause tachycardia (a heart rate disorder with faster heartbeats than usual, more than 100 beats per minute). It can also cause a feeling of pressure in the chest. Heart damage can continue for up to 2 weeks in mild cases or even 6 weeks in more severe cases.

COVID-19 can sometimes also affect the eyes, causing conjunctivitis, blurred vision or flowing eyes.

If food and drinks no longer have taste or taste differently from usual and are also associated with loss of smell – it is clear that the COVID-19 virus is present. Almost 80% of people who have tested positive have lost their taste and/or smell.

The safest way to differentiate a cold from COVID-19 infection is testing for the COVID virus. The level of antibodies can also be tested, after a certain period of time after the end of the infectious episode through a blood test. Antibodies are the proteins that the body makes to help in the fight against an infection. It's not certain if the presence of antibodies protects the body against a new COVID-19 infection, but there are still studies that show that people who have these antibodies are less likely to get the disease again.