Dear Mr. Anthony,
I am writing this email to request you to please grant me a sick leave for two days as I am not feeling well. On consulting with the doctor, I have been found to be infected with some stomach infection which has led to severe vomiting.
I am hopeful that you will consider my situation and will grant me with a short leave. I have requested Mr. Richard Smith to fill for me for this duration. Moreover, I will be available on call during this time as and when needed.
Thanking you.
Sincerely,
Adam Gibbs
Source: Sick Leave Email to Boss