Middle back pain is most often a symptom of muscle strain or poor posture, but it can also signal problems with spinal discs, bones, or internal organs like the gallbladder or kidneys. The thoracic spine, which runs from the base of your neck to the bottom of your rib cage, is less prone to injury than the lower back, yet studies estimate that 15% to 35% of adults experience thoracic pain in any given year.
Muscle Strain and Postural Stress
The most common cause of middle back pain is soft tissue injury: sprains and strains in the muscles and ligaments that support the thoracic spine. This can happen from lifting something awkwardly, playing sports, or even sleeping in an odd position. Repetitive strain injuries also affect both blue- and white-collar workers, from warehouse staff to people who type all day.
Prolonged sitting with a forward-leaning head and rounded upper back increases the load on your spinal muscles and joints. Over hours at a desk, these postural changes compound, and the muscles between your shoulder blades fatigue and start to ache. This kind of pain typically improves with rest and gentle movement, and it often resolves within a week. If it doesn’t, that’s a signal to get it evaluated.
Herniated Discs in the Thoracic Spine
Disc herniations are far less common in the middle back than in the lower back, but they do happen and can be surprisingly tricky to diagnose. A bulging disc in the thoracic spine can compress nearby nerves, causing pain that doesn’t always feel like a back problem. Some people experience chest tightness, abdominal discomfort, or even nausea. Others develop leg weakness, gait instability, or urinary changes. Because these symptoms mimic gastrointestinal or heart issues, thoracic disc herniations are frequently misdiagnosed on the first visit. An MRI is typically needed to confirm the problem.
Compression Fractures
A vertebral compression fracture happens when a weakened bone in the spine partially collapses. The hallmark symptom is sudden back pain that gets better when you lie down and worse when you move. You might also notice tingling, numbness, or muscle spasms near the fracture site. In mild cases, some people don’t feel symptoms at all.
Osteoporosis is the primary driver. As bones lose density with age, even a minor fall or twisting motion can cause a fracture. The risk climbs steeply after age 50, particularly for postmenopausal women. By age 80, an estimated 40% to 50% of people have experienced at least one compression fracture. Cancer that has spread to the spine can also weaken vertebrae enough to cause breaks.
Ankylosing Spondylitis
If your middle back pain is worst in the morning or after sitting for a long time, and it improves once you start moving, an inflammatory condition called ankylosing spondylitis is worth considering. This is a type of arthritis that primarily targets the spine. It usually starts in the lower back but can progress upward into the thoracic region over time.
Many people experience mild, episodic flare-ups of pain and stiffness. Others develop severe, ongoing symptoms. In advanced cases, the vertebrae can fuse together, creating a rigid spine with limited flexibility. A specific gene called HLA-B27 increases the risk, though carrying it doesn’t guarantee you’ll develop the condition.
Gallbladder Problems
Middle back pain between the shoulder blades, especially on the right side, can be referred pain from the gallbladder. Gallstones produce episodes of intense upper abdominal pain that radiates to the upper back or right shoulder blade in roughly 60% of cases. The pain tends to strike in the late evening or at night, often lasts four to six hours, and may come with nausea or vomiting. It can worsen when you breathe in deeply.
In some cases, gallbladder-related back pain becomes chronic and persistent, with sharp flare-ups. One documented pattern involves pain at the mid-to-lower thoracic level (around the T10 to L2 vertebrae) on the right side. Because this pain can feel purely muscular, people sometimes treat it as a back problem for months before the true cause is identified.
Kidney Conditions
Kidney stones and kidney infections both produce pain that can settle in the middle or lower back, usually on one side. The pain from kidney stones is often described as intense and wave-like, sometimes causing people to writhe and shift positions trying to find relief. Accompanying symptoms like flank pain and urinary changes (burning, frequency, or blood in the urine) are strong indicators that the kidneys are involved rather than the spine itself.
Lung and Heart-Related Causes
Pleurisy, an inflammation of the lining around the lungs, causes sharp pain that worsens with breathing or upper body movement and can spread to the back and shoulders. Pneumonia can produce a similar aching pain in the middle back, usually alongside cough, fever, and difficulty breathing.
A thoracic aortic aneurysm, a bulge in the large blood vessel running through the chest, can cause back pain as it grows. Other symptoms include cough, shortness of breath, and chest tenderness. If the aneurysm ruptures or tears, the pain becomes sharp and sudden in the upper back and radiates downward, sometimes extending to the chest, jaw, neck, or arms. This is a life-threatening emergency.
Warning Signs That Need Prompt Attention
The large majority of middle back pain is benign. In one study of 1,000 emergency department patients with back pain, about 81% had a straightforward musculoskeletal cause. But certain symptoms dramatically increase the odds that something more serious is going on.
Fever is the single strongest warning sign, raising the likelihood of serious pathology more than any other individual factor. Unexplained weight loss, inability to urinate or new loss of bladder control, numbness in the groin or inner thighs (called saddle anesthesia), and flank pain are also significant red flags. Pain that wakes you from sleep, pain that started after a fall or trauma, and pain accompanied by neurological changes like leg weakness or difficulty walking all warrant timely evaluation rather than a wait-and-see approach.