You should first of all talk to your GP. When you are preparing to return to work after some weeks off sick, you may also need advice from your union rep, if available, or another independent adviser.
Involving your GP is very important. The GP will have knowledge of specific medical factors that need to be taken into account, which may limit your work activities, for a time or permanently. If necessary they will be able to issue you with a fit note that will recommend to your employer a phased return to work, altered hours, amended duties or workplace adaptations.
For more information, see the TUC advice on fit notes.
Your GP will also be aware of any other treatment, e.g. physiotherapy that may still have to be completed (see the Dealing with Doctors section).
GPs may be contacted by an Occupational Health doctor or nurse for information, e.g. if you need specific help with your health in relation to work. Any information provided by a GP is subject to 'patient confidentiality' and you giving your prior consent.
If you are in England or Wales and you have been off work for four weeks or more your employer may refer you to the new Fit for Work service for a voluntary occupational health assessment. (Also see our FAQ on returning to work.)
Your employer should risk assess any proposed changes to your existing working arrangements, to make sure they do not introduce a new risk. 'Risk assessment' just means carefully checking how these changes could affect you and discussing the proposals with you, monitoring the situation and making any necessary adjustments.
If you are disabled, your employer also owes you a duty to consider any reasonable adjustments to help you return to work. There is more information about this in our Disability Discrimination section.
Rehabilitation means the process of getting yourself back to work, either to the same job or to an agreed alternative that is appropriate to your medical condition. It usually involves a 'return to work' agreement (often in writing) between you and your employer.
For further information see the TUC's Rehabilitation web pages.