Dear customer, it is a pleasure to be able to assist you at this time, with what you tell me seems to be associated with a musculoskeletal condition which usually responds satisfactorily to treatment with specific medications such as meloxicam in 15 mg tablets, in fact, there are specific pharmacological combinations, which have analgesic with corticosteroid drugs and vitamin B12 which has a potent analgesic action, anti-inflammatory and nourishing action in the musculotendinous region thanks to vitamin B12, apart from this it can be very useful to start with cold and heat therapy, placing 5 minutes of cold followed by 5 minutes of heat every 12 hours, in the morning and at night, it is also important to rest together with the reduction of inadequate weight lifting or exaggerated force, which can trigger a major muscle contracture. Chest pain of cardiac origin is usually a situation that must be ruled out by the doctor in person, after a physical examination, it can often be accompanied by pain in the jaw and left arm, but this does not seem to be your case, as it is pain in the back and left arm, in addition, the pain of cardiac origin, which usually causes a lot of concern in patients, is usually constant and does not disappear during certain hours of the day, in your case this pain seems to occur at night when the muscles of the body are cooled by the night's rest or with the cessation of physical activities of the day, with the recommendations and treatment that I provided you with you should improve satisfactorily, at least while you manage to go to the doctor, I would like you to keep me informed of your health situation, it will be a pleasure to assist you and guide you in everything I can, taking into account that your doctor after a thorough physical examination may consider performing paraclinical tests such as a shoulder ultrasound to see if there are musculoskeletal alterations that may be compromising the sensitivity in the shoulder joint.