If you are sick longer than the time allowed by the self-declaration, you must get in touch with your doctor in order to get a medical certificate. If the doctor regards sick leave necessary, he/she will issue a medical certificate for the required period.
The doctor will also assess whether full sick leave (100 per cent) is required, or whether you are able to perform some of your work and only need partial sick leave. For example you may be on 50 per cent sick leave and work 50 per cent of the time. The employer shall adjust your duties if necessary, and follow you up while on sick leave. Active sick leave or other measures from NAV may be considered.