A leave application for headache is a short formal letter students write when they need leave because of a headache. A clear application helps the teacher or principal understand the situation quickly.
Below are simple sample formats you can edit and use.

Sample 1: One Day Leave for Headache
To,
The Principal / Class Teacher
[School Name]
Date: [Write Date]
Subject: Leave application for headache
Respected Sir/Madam,
I am suffering from a severe headache and will not be able to attend school today. Kindly grant me leave for one day.
I shall be thankful to you.
Yours obediently,
[Your Name]
Class: [Class]
Roll No: [Number]
Sample 2: Half Day Leave
To,
The Class Teacher
[School Name]
Date: [Write Date]
Subject: Application for half day leave due to headache
Respected Sir/Madam,
I have a bad headache and need to rest. Kindly allow me half day leave today.
Thanking you,
Yours obediently,
[Your Name]
Sample 3: Leave for Two Days
To,
The Principal
[School Name]
Date: [Write Date]
Subject: Leave application for headache
Respected Sir/Madam,
I have been suffering from a severe headache since last night. The doctor has advised rest. Kindly grant me leave for two days from [start date] to [end date].
Yours faithfully,
[Your Name]
Class: [Class]
Sample 4: Simple Headache Leave
To,
The Class Teacher
[School Name]
Date: [Write Date]
Subject: Application for leave due to headache
Respected Sir/Madam,
I have a headache and cannot attend school today. Kindly grant me leave.
I shall remain thankful to you.
Yours obediently,
[Your Name]
These samples for a leave application for headache can be customized with your details.