It is a professional way to address your boss or teacher. Use professional tone, like “Dear Mr. /Ms. /Mrs. Second-Name of the Receiver.”
Early on in the letter, mention that you would not be able to attend the educational institution/office as you are suffering from a specific injury or sickness.
Bring up your doctor’s prescription or professional opinion on your sickness or injury. It is even better if you attached a cop of his/her prescription.
Request the receiver to grand you leave- based on the doctor’s prescription and on the chances of your recovery.
Either you are a student or an employee; assure the concerned authority that absence wouldn’t affect your work. And you will complete all due works once you are back.
Show your gratitude for the receiver’s consideration.
Your closing salutation should sound polite and professional. Like, “Yours Faithfully,” “Respectfully Yours,” and “Yours Sincerely” etc.
Sample of a Sick Leave Letter
Customer Relationship Officer
MNO Bank Limited
Birmingham, AL 12345
March 20, 2013
MNO Bank Limited
Dear Mr. Hammer,
I am writing this letter to notify that I would not be able to attend office for the next two days that is, from 21 to 22 March, as I have been suffering from severe food poisoning since last night.
My doctor has prescribed bed rest to keep my body hydrated for the next two days. I have enclosed the copy of the doctor’s prescription and medical report for your satisfaction.
I know my absence can affect the overall workload of the office. However, I will make sure to complete all the pending tasks once I am back to my seat on 23rd March. For any additional requirement or information, you can contact me at 0011-12345678 or email me at firstname.lastname@example.org.
Thanks you so very much for considering my sick leave request. Looking ahead for your approval!