What to say when you feel a pain in your body
 

243. Put your hand on the place where you feel pain and say:

بِسْمِ اللهِ

Bismillaah.

In the Name of Allah (three times).

Then say:

أَعُوذُ باللهِ وَقُدْرَتِهِ مَنْ شَرِّ مَا أَجِدُ وَأُحَاذِرُ

'A'oothu billaahi wa qudratihi min sharri maa 'ajidu wa 'uhaathiru.

I seek refuge in Allah and in His Power from the evil of what I find and of what I guard against.

Reference: Muslim 4/1728.