Thanks for your question on Health Care Magic. I can understand your friend's situation and problem.
Possibility of
musculoskeletal pain is more but better to rule out heart related diseases because he is having left sided
chest pain.
So first get done ecg and 2d echo to rule out cardiac diseases.
If both these are normal then no need to worry for heart diseases.
Musculoskeletal pain is more likely in his case.
So ask him to follow these steps for better symptomatic relief.
1. Avoid heavyweight lifting and strenuous exercise.
2. Avoid bad postures in sleep.
3. Avoid movements causing pain.
4. Apply warm water pad on affected areas.
5. Start painkiller and
muscle relaxant drugs.
He will mostly improve in 1-2 weeks.
Hope I have solved your query.
Wishing good health to your friend.
Thanks.