Dear Nk.civil, hello.
Pain present in one side of the head is usually seen in case of Migraine
. There are many trigger factors which increase migraine pain. These are :-
1. Lack of sleep
3. Missed meals
5. Dairy products
6. Stressful exercise
You can judge whether your pain is associated with any of these and workout accordingly.
Please also have your eyesight checked for any Refractive error
Also note whether your headache is associated with nausea/vomitting, gidiness, photophobia
, dislike for loud noise, etc.
Hope this advice is useful to you. Thanks.