It’s “normal” for people to experience mild side effects after having the Covid-19 vaccination, GPs have said. But when does a mild side effect turn into something you need to seek help for?

The most common side effects of the jab, which impact around one in 10 people after being vaccinated, include muscle pain; chills, joint pain, fever, and nausea.

Such side effects appear to be less common in those aged 55 and over, and more common in those aged 16 to 55 years old. 

Other common side effects you might experience include: a lump where you had the injection, a sore arm, fever, vomiting and flu-like symptoms (like a high temperature, sore throat, runny nose, cough and chills).

Professor Martin Marshall, chair of the Royal College of GPs, said: “It is normal, as with most vaccinations, for some patients to experience mild side effects – such as a sore arm or fatigue – after receiving their jab, which usually last no longer than a few days.” 

If you do have mild side effects – like a headache or joint pain, for example – it’s recommended you treat them with painkillers, such as paracetamol.

Uncommon side effects of the vaccine, affecting roughly one in 100 people, include: dizziness, decreased appetite, abdominal pain, enlarged lymph nodes, excessive sweating, and itchy skin or a rash.

Rare side effects, which impact one in 1,000 people, include temporary one-sided facial drooping and in very rare instances, severe allergic reactions.

If symptoms become worse or start to cause concern, patients should seek medical assistance by calling 111 or their GP practice, says Prof Marshall. Or, in an emergency, they should phone 999.

In very rare instances, some people have experienced anaphylaxis after having the jab – this would require emergency attention.

Signs of anaphylaxis include: sudden and rapid progression of symptoms, life-threatening airway and/or breathing and/or circulation problems, and skin changes (such as the appearance of rashes). But rashes alone aren’t a sign of anaphylactic reaction, according to Public Health England’s green book. 

People who experience any side effects, whether mild or more severe, can report these on the Yellow Card website to help inform vaccine safety.

“The Covid-19 vaccine is our best protection against the virus,” says Prof Marshall, “and we would encourage anyone who has been invited for their first dose to come forward – and to return for their second dose, when advised, to ensure maximum protection.

“Patients should be assured that both Covid-19 vaccines currently being used in the UK have been approved by the MHRA and have gone through a rigorous process to ensure they are both safe and effective.”