Middle back pain most often comes from strained muscles, poor posture, or minor injuries to the soft tissues surrounding the thoracic spine, the 12 vertebrae between your neck and lower back. It’s less common than lower back pain, affecting roughly 24% of people over a lifetime compared to 54% for the lower back, but it can be just as disruptive. The causes range from completely benign to occasionally serious, so understanding what’s behind your pain helps you know what to do next.
Muscle Strains and Ligament Sprains
The most frequent cause of middle back pain is a soft tissue injury. A strain means a muscle or tendon has been twisted, pulled, or torn. A sprain means a ligament has been stretched or torn beyond its normal range. Both can happen from a single event, like lifting something heavy with poor form, or from repetitive stress over time.
Acute strains typically follow a specific moment: you twisted awkwardly, reached overhead at a bad angle, or caught something heavy. Chronic strains develop more gradually from repeated movements, like bending and lifting at work, or spending hours in positions that overload the muscles supporting your mid-spine. Sprains tend to follow a fall, sudden twist, or direct blow to the body. In both cases, the pain usually feels like a dull ache or tightness that worsens with movement and improves with rest. Most soft tissue injuries in the middle back heal within a few weeks with basic care like gentle movement, over-the-counter pain relief, and gradual return to normal activity.
Posture and Prolonged Sitting
Sitting at a desk for hours, hunching over a phone, or slouching on a couch creates a predictable pattern of muscle imbalance. The chest muscles and upper trapezius tighten while the muscles between and below your shoulder blades weaken. This combination pulls the shoulders forward and increases the natural curve of the thoracic spine, placing extra stress on the joints around the T4-T5 segment in particular.
Over time, this creates a cycle: the rounded posture loads certain spinal segments unevenly, those segments become stiff and sore, and the soreness makes you less inclined to move, which worsens the imbalance. The fix targets both sides of the equation. Stretching the chest, upper trapezius, and the muscles along the side of your neck addresses the tightness. Strengthening the muscles that stabilize your shoulder blades (particularly the lower trapezius and the serratus anterior, which wraps around your ribcage) helps restore balance. Simply “sitting up straighter” without addressing these imbalances rarely works for long.
Compression Fractures
Compression fractures happen when a vertebra collapses under pressure, and they occur most often in the thoracic spine. Osteoporosis is the leading cause. As bones weaken with age, fractures can result from surprisingly minor forces: getting out of a car, sneezing hard, coughing, or twisting suddenly. In people with severe osteoporosis, there may not even be a clear triggering event.
Trauma from falls or car accidents can also cause compression fractures in people with healthy bone density, though this requires significantly more force. In rarer cases, cancerous tumors that have spread to the spine weaken the vertebrae enough to cause fractures. The pain from a compression fracture is usually sudden, sharp, and centered on a specific spot in the middle back. It often worsens when standing or walking and eases when lying down. People over 65, those with known osteoporosis, and anyone on long-term steroid medications are at highest risk.
Thoracic Disc Herniation
Disc herniations in the middle back are uncommon. Symptomatic thoracic disc herniations are estimated to occur in roughly 1 in 1,000 people at most, and thoracic disc surgeries make up less than 4% of all disc procedures. The thoracic spine is more rigid than the neck or lower back because the ribs provide structural reinforcement, which limits the kind of movement that typically causes discs to bulge or rupture.
When a thoracic disc does herniate, it can press on nearby nerves, causing pain that wraps around the ribcage, numbness or tingling in the trunk, or in serious cases, weakness in the legs. Imaging studies do find incidental (painless) thoracic disc herniations in about 6.5% of people being scanned for other reasons, which means having one on an MRI doesn’t necessarily mean it’s causing your symptoms.
Inflammatory Conditions
Ankylosing spondylitis is a type of inflammatory arthritis that primarily affects the spine. It usually starts with lower back and hip pain and stiffness, but over time it can progress upward into the thoracic spine. A hallmark feature is that the pain worsens during rest or inactivity, often flaring in the middle of the night or after prolonged sitting, and improves with movement and exercise. This is the opposite of most mechanical back pain, which tends to feel worse with activity.
When ankylosing spondylitis reaches the middle back, it can affect the joints where the ribs connect to the spine, making it difficult to take deep breaths. In severe cases, the vertebrae gradually fuse together, creating a rigid, inflexible spine. This condition is most common in younger adults, typically appearing before age 45, and it progresses slowly over years. Pain that consistently improves with exercise and worsens with rest is a distinguishing clue.
Referred Pain From Internal Organs
Not all middle back pain originates in the spine. Several internal organs can send pain signals to the mid-back area, a phenomenon called referred pain. Gallstones often cause pain between the shoulder blades or in the right side of the mid-back, especially after eating fatty meals. Pancreatitis can produce similar pain that radiates to the back from the upper abdomen. A ruptured spleen can cause pain between the shoulder blades, known clinically as Kehr’s sign.
Kidney infections and kidney stones can also cause pain in the middle to lower back, typically on one side. The key distinction with referred pain is that it usually comes with other symptoms: nausea, fever, changes in urination, or abdominal discomfort. Mid-back pain that appears alongside these symptoms, especially if it’s unrelated to movement or position, points toward an organ-related cause rather than a spinal one.
Rare but Serious Causes
In uncommon cases, sudden severe middle back pain can signal a vascular emergency. A ruptured aortic aneurysm, where part of the body’s main blood vessel weakens and tears, causes internal bleeding that can lead to heart attack or stroke. Aortic dissection, a tearing of the inner wall of the aorta, can also produce intense back pain and is life-threatening without immediate treatment. These events are rare, but the pain is typically sudden, severe, and unlike anything you’ve felt before, often accompanied by dizziness, shortness of breath, or a feeling that something is profoundly wrong.
When Imaging Is Needed
Most middle back pain doesn’t require imaging. According to guidelines from the American College of Radiology, uncomplicated thoracic back pain without neurological symptoms or red flags is often a self-limited condition that resolves without X-rays or MRIs. Imaging becomes appropriate after about six weeks of physical therapy and conservative treatment that hasn’t improved things.
Earlier imaging is warranted in specific situations: if you’ve had significant trauma, if you’re over 65 or have osteoporosis, if you take long-term steroids, or if there’s suspicion of cancer or infection. Numbness, tingling, or weakness in the legs alongside mid-back pain also prompts earlier investigation, typically with an MRI. For people with risk factors for compression fractures, a simple X-ray is often the first step. The goal is to avoid unnecessary imaging for routine muscle pain while catching the less common causes that need specific treatment.