Both Influenza and COVID-19 are both incredibly contagious illnesses that affect the respiratory system within the body. You may think that they are incredibly similar and, while some symptoms do overlap, they are actually caused by two different viruses.

COVID-19, as probably the entire world is aware, was first spread from the virus SARS-COV-2, an infection that first began in 2019 and soon became the focus of the global pandemic of 2020 and 2021. It’s been known to spread a lot easier than flu, and, due to the lack of vaccines when the virus began to spread, became a lot more fatal than influenza has in the modern age. The symptoms for COVID-19 is also known to be a lot longer than flu.

Influenza, on the other hand, is a virus that has been around for so long that it’s difficult to determine when it first began to affect humans. It’s been theorised that the first flu epidemic happened in China at around 6,000 BC, but there have been possible descriptions of influenza in Greek writing from the 5th Century BC. Modern flu symptoms usually last between 2-3 days, however, could result in longer diseases such as pneumonia.

Both viruses have a lot of overlapping symptoms. A lot of the time, a SARS-COV-2 Antigen test is used to determine whether the illness you have is COVID-19 or not.

The symptoms that the two viruses share are:

• — Fever
• — Cough
• — Muscle pain/Body aches
• — Headaches/Migraines
• — Vomiting/Diarrhoea
• — Change or loss of taste or smell
• — Sore throat
• — Shortness of breath/difficulty breathing
• — Fatigue
• — Runny/Stuffy nose

Both COVID-19 and flu are both spread through close contact with an infected person, where particles or droplets of saliva are spread into the air and inhaled when they cough, sneeze, or talk.
Both viruses can also result in longer term, more serious illnesses, and certain groups of people are more vulnerable to both, including: the elderly, people with underlying or unknown medical conditions, pregnant women and infants.

Some of the longer complications both viruses can result in are:

• — Pneumonia
• — Cough
• — Breathing/Respiratory failure
• — Sepsis
• — Cardiac injury such as heart attacks or strokes
• — Organ failure
• — Sore throat
• — Fluid in the lungs
• — Worsening of underlying medical conditions that affect the lungs, heart or nervous system

The differences are becoming increasingly smaller with the less harmful variants of COVID-19, but it is important to realise how they differ.

While both viruses can be spread up to 1 day before the person experiences symptoms, it’s typical for someone with COVID-19 to take longer to show symptoms than flu. Influenza symptoms tend to come on extremely quickly, and die off much the same, while COVID-19 can range from a multitude of symptoms depending on the person.

It will also take longer to get over COVID-19 than flu; COVID symptoms will last between 5 and 10 days, often longer dependant on severity of symptoms.

Long lasting illnesses caused by COVID-19 seem to be more severe in some people, where the UK has seen more otherwise healthy people hospitalised from COVID-19 in a much shorter timeframe than when with flu.

One of the best ways to tell the difference between flu or COVID-19 if you are experiencing symptoms is to simply take a LFR or PCR test. This will determine whether or not it is COVID-19, but typically does not test for other viruses such as flu.

If you experience any extreme symptoms while suffering from either viruses, however, you should phone 999 (or the equivalent emergency number in your country) if you are failing to breathe properly or have an extreme high temperature.