Hello ,
There might be due any strain over the joints or may also be due to early arthiritis changes in the joint .
There may be any rotator cuff weakness .
Kindly do physiotherapy exercise for the shoulder .
Keep hot pack applications over the shoulder
Take Tab Nurokind LC / OD for 1 month and tab Tendofit / OD for 1 month , Tab Hifenac -p / BD for 1 week
Next Steps
Physiotherapy for shoulder