name of u r place, 
Respected sir,
                      I ....... of class 10. I beg to state that i have been suffering from jaundice since from 2 days. I am  unable to attended the half-yearly examination due to this reason.  therefore I request you to accept my absence for exams .
I shall be much obliged to you.
                               Thanking you ,
                                                                             yours faithfully,
                                                                               u r name.
4 4 4