Your GP may advise a short period of rest, perhaps with an ice pack, but long periods of inactivity can worsen the injury by weakening affected muscles or tendons. Painkillers prescribed by your GP may be necessary, but they can conceal the pain and prevent your body's natural alarm bells warning you about potentially irreparable damage.
For persistent pain, the GP is likely to refer you to a specialist.
You may also need a doctor's letter to your employer, asking for alternative work on lighter duties. Your doctor will issue you with a fit note, formally known as a Statement of Fitness for Work. After your doctor has assessed you for your fitness for work, they will either use the fit note to advise your employer that you are not fit for work or that you may be fit for work as long as the employer follows the advice written on the fit note. The advice can include recommendations for a phased return to work, altered hours, amended duties or workplace adaptations. You only need a fit note from a doctor after seven days off work sick.
Employers can take a copy of the fit note and you should keep the original. Your fit note will not be sent electronically to your employer.
There is further advice on the 'fit note' on the TUC website.