Hi
Welcome to the MedHelp forum!
What you have is probably Scalene Myofascial Pain Syndrome. When scalene muscle is the cause of pain, the pain is referred to chest, inner lining of scapula (shoulder bone), shoulder, posterior and lateral sides of the arm right up to the thumb and index finger. It could also be due to pinched cervical spinal nerve or due to TMJ or a combination of both. Hence a MRI of cervical spine should be done along with a dental checkup to look for causes of TMJ.
Other than this it can be inflammation of veins or phlebitis, inflammation of lymph channels or lymphangitis, deep vein thrombosis or compartment syndrome.
Since I cannot examine your father and know other related conditions he may be having, nor is a detailed history possible on net, I have listed the various possibilities that should be looked into. Please consult your PCP for primary examination followed by proper referral.
Take care!
Could be a problem that is coming from your neck. Worth having it checked out! Sometimes a rotator cuff tear will cause upper arm pain like you are describing but not often seen in both upper extremities at the same time. Have it checked out!
It could be a number of things, I have the same problem and mine is Fibromyalgia and chronic Myofascial Pain Syndrome. Until your Doc checks it out you won;t know,
Go to the Emergency Room!