Possible causes of arm pain include: Angina Brachial plexus injury Broken arm Broken wrist/broken hand Bursitis Cancer (malignancy), primary or metastatic Carpal tunnel syndrome Cervical dystonia (spasmodic torticollis) De Quervain s tenosynovitis Dislocated elbow Fibromyalgia Heart attack Herniated disk Rheumatoid arthritis Rotator cuff injury Sprains and strains Tendinitis Tennis elbow Thoracic outlet syndrome Ulnar nerve entrapment. Self-care Even serious arm injuries can be helped initially with home treatment. If you think that you have a broken arm or wrist, apply ice packs to the affected area and use a sling to help hold your arm still until you can get medical care. If you have a compressed nerve or repetitive strain injury, be consistent about therapy; maintain good posture; and take frequent breaks at work and during repetitive activities, such as playing an instrument or practicing your golf swing.. Rest. Take a break from your normal activities. Ice. Place an ice pack or bag of frozen peas on the sore area for 15 to 20 minutes three times a day. Compression. Use a compression bandage to reduce swelling. Elevation. If possible, elevate your arm to help reduce swelling.