Lung pain is difficult to diagnose as there are a number of lung complaints which can cause pain and a large number of other conditions which can cause chest or upper back pain or shoulder blade pain. There is more information about chest related pain at Wrongdiagnosis.com and About.com's Heart Health Center.
Chest pain can be variously described as varying from sharp to dull, precise in position or vague and deep, pressure or burning, lasting a short time or longer, worse with changing position, coughing, breathing deep, eating, being physically active as well as other potential factors.
The pain of pleurisy is sharp and worse with coughing and breathing deep and better with splinting the painful side by arm pressure and is usually well localised by the patient. Other medical conditions which can give chest pain include infections such as pneumonia, lung collapse (pneumothorax), blood clots (pulmonary emboli), tumours and fluid on the lung. Any process which damages the lung can be a source of lung pain. In most of these cases the patient will be obviously unwell and immediate medical attention should be sought.
Upper back muscle pain can be felt around the upper back and may be worse with breathing in deep or heavy activity, often felt as upper back pain between shoulder blades. Upper back pain symptoms can vary widely from a mild ache to a strong, limiting pain to a sharp, stinging pain from an injured spinal joint.
Lung pain may also be felt lower down in the chest and could be mistaken for middle back pain or mid back pain, although these terms are often used along with upper back pain for pain in the thoracic region.
Upper Back Pain
Upper back pain is moderately common but less than neck or back pain and can occur throughout the thoracic spine including round to the front. Upper back pain during pregnancy is also not as common as low back pain and sacroiliac joint pain but can be troublesome and your physiotherapist should be able to help with this. Upper back pain is often one sided so upper back pain left side just indicates that the stressed or injured structures are on the left side of the spine.