Look it is bound that arthritis causes only after 50 sometimes it causes at young age also. Basically the wear and tear of the joints causes joint pain which often arises at older ages. Start some exercises which includes shoulder movements, that relieve some pain.
If at all you had any shoulder injury ever before then may be for that reason the pain might be persisting.
Shoulder arthritis typically affects patients over 50 years of age. It is more common in patients who have a history of prior shoulder injury. There is also a genetic predisposition of this condition, meaning shoulder arthritis tends to run in families. Immediately consult orthopedic surgeon.
No but it sounds as if you should not over do it! If it is arthritis the weather alone can trigger bad days. Exercise is important but in moderation.
Shoulder problems are pretty common as we get older. My mom had successful rotator cuff surgery last year; she's in her 70s and had never been athletic.