People working under any organization use a leave letter to apply for leave of absence from office. Any leave letter should be short and brief and to the point.
In the leave letter, the person should clearly specify his leave period like starting date to ending date. In order to get leave sanction, one must provide a valid reason. Reason can be of any thing like visiting a doctor or it could be even some personal problems that one cannot mention in letter.
In case of personal problems, then you may just provide a hint of the problem if you can or else you can just mention that it cannot be mentioned. Detailed info is not required in such cases.
When you write a leave letter to avail leave of absence, make sure that you write a formal leave letter in formal tone and content. Finally before ending the letter, you must thank the employer or in general the addressee. It is necessary.