While a poor sleeping position may cause arm pain, there are multiple causes of arm pain to consider, including angina, fibromyalgia and herniated disc disease, according to Mayo Clinic. Rheumatoid arthritis, rotator cuff injuries, tennis elbow and bursitis are additional causes. Some causes of arm pain require immediate medical evaluation.
If pain in the arm has a sudden onset accompanied by squeezing or fullness in the chest, this may indicate a heart attack, notes Mayo Clinic. Arm pain that is brought on by exertion but is relieved by resting may also signal heart disease. Severe pain or swelling in the arm, sudden injury to the arm, or trouble moving or turning the arm are also cause for immediate evaluation by a medical professional.