The University states that illness lasting less than 10 days does not require certification by a doctor. Longer periods need a doctor's note, but you will need to have seen a doctor or nurse for the practice to provide you with a sick note.
For periods of illness shorter than 10 days: If the student has been seen in surgery by either a doctor or a nurse the surgery will be happy to provide a print out of the students last consultation with that clinician (small charge payable by student) as evidence of their visit to the surgery regarding the condition concerned.
If you are unwell and absent from work for up to seven days you should self-certificate using form "SC2", available from your personnel department. Please note, each and every day should be counted, including weekend days and days that you might not ordinarily work.
Sickness causing absence of seven days or more requires a doctor's note. Self Employed Persons: The same regulations apply as for employees, except that a "SC1" form is used instead.