Vaccines, like any medication, can cause side effects. In the majority of people these tend to be mild and don't last longer than a few days and some people don't get any side effects at all. Common side effects should have been explained to you by your vaccination provider.
To find out more about side effects of vaccines, visit NHS choices.
It is important for people to report problems experienced with medicines or medical devices as these reports are used to identify issues, which might not have been previously known.
If you are concerned that you or your child has experienced a side effect after a vaccination, this can be reported on the Yellow Card.
Information about what to include in a Yellow Card report can be found on this document (opens PDF).
The Yellow Card Scheme is run by the Medicines and Healthcare products Regulatory Agency (MHRA) to pick up unexpected problems or new side effects. The MHRA will review the product and, if necessary, take action to minimise risk and maximise benefit to the patients.
The video below was produced by the MHRA. The video explains that reporting side effects makes medicines safer.