Most humbly, I would like to state that my name is ______ (name) and I am a student of ______ (department) having college registration number _________ (mention number).
This is to inform you that I have been suffering from ________ (high fever/cold/cough/mention reason) from the last ____ (duration). The doctor has advised me for a bed rest. So, I request you to grant me ____ (days) leave.
Kindly, approve my leave application and allow me to take leaves from __/__/____ (date) to __/__/____ (date). I promise you that this will not affect my studies. If you need to contact my parents regarding this matter, you can contact them at the below-mentioned contact details.
_________ (College roll number)
_________ (Contact details)