You do not need a doctor’s note for any period of illness lasting 7 days or less. Your employer however may request that you complete a self-certification form, available here, or similar form from your employer.
If a longer absence is likely, you will need to obtain a “Statement of Fitness for Work” from the hospital doctor or GP who has indicated that you are unfit for work.
Please note that you do not need a final or signing off note to enable you to return to work; you can simply return to work when your note ends. If you do not feel able to do this, please book a telephone consultation with your GP.
If you are likely to be off work for some while, it helps to keep a record of your sick note dates, so you are aware when your current note is coming to an end.
With regards to benefits or support you may be entitled to, visit the direct.gov website here.