Most of the time, this pain is neither permanent nor serious. Being anxious or stressed out about your pain in shoulder and arm, you will increase your chances of muscle spasm, which is itself both a source and amplifier of all kinds of pains.
The shoulder joint
The shoulder blade and arm bone are connected by a ball and socket joint with a large range of movement. The joint socket is shallow which enables easy motion in the arm. The ball of the upper arm is larger than the shoulder socket that holds it and the shoulder is kept stable, anchored by muscles, tendons, and ligaments.
The rotating cuff is made up of four muscles that surround the arm bone, enabling it to rotate. It is this cuff that keeps the shoulder steady when the arm bone rotates. This mobile joint tends to be more susceptible to injury which causes pain in the shoulder area.
Shoulder and arm pain can be caused by one or more of the following causes
1) Soreness of the tendon
Any swelling, inflammation, tearing, or changes in bone around the joining tendons may cause pain when a person tries to move the arm above the head, behind the back, or straight out in front. This may cause pain by soreness of the tendon, the cord that attaches a muscle to a bone. The tendon of the rotator cuff which connects the part of the shoulder is unable to rotate because of the injury.
2.) Soreness of the fluid sac
Another common cause of shoulder pain is soreness of the subacromial bursa, the sac of fluid under the highest part of the shoulder. This sac of fluid cushions the tendon that joins arm and shoulder blade. The fluid in the sac makes it easy to rotate the arm by lubricating the area.
3) Strain from overexertion
Shoulder and arm pain occurs after frequent use of shoulder area in activities such as painting, lifting or playing a sport, which requires lifting arms often. Pain is caused by overuse of the tendons.
4) General wear and tear as one becomes older
Although shoulder and arm pain is caused commonly by sporting activities and manual labor, the main source of shoulder problems appears to be the natural age-related degeneration of the surrounding soft tissues found in the rotator cuff.
5) Dislocation or injury
Accidents may cause injuries and dislocation, resulting in shoulder and arm pain. This is found common while playing sports or as a result of violence or other trauma. When there is a bone fracture it can be a cause of arm and shoulder pain.
6) Diseases may cause shoulder and arm pain
Diseases in the body such as gallbladder, liver, or heart disease, or disease of the cervical spine of the neck may generate pain that travels along nerves to the shoulder area.
7) Infection may be a reason
Sometimes bacterial or viral infections may develop shoulder or arm pain if the infection invades blood and bones. Staph bacteria invade the bloodstream and may cause septic arthritis of the shoulder and arm.
8) Some medical conditions may cause pain
Certain medical conditions and personal habits can increase the risk of developing this type of shoulder pain. Sometimes it may also be due to the side effects of some medication. People with heart problems and long-term illnesses such as bone cancer or multiple sclerosis may also develop shoulder or arm pains.