Chest or Stomach pain when the specialist can't find a source?
Neuromusculoskeletal Causes of Trunk Pain
Although the heart or stomach are classically responsible for discomfort in these areas, occasionally they’re not. Since muscles, connective tissue, neural networks, and the skeletal framework make up the physical structure of the torso, these structures should be assessed when the organs are ruled out.
When structural systems fail, they can mimic internal medical emergencies or chronic visceral illnesses, leaving patients searching for answers through endless normal scans and negative diagnostic work-ups. If a specialist has given your organs a clean bill of health, it’s time to look at the architectural and neural framework of your trunk.
Here are the primary culprits that can cause unexplained chest, flank, or abdominal discomfort:
Upper Trunk & Chest Wall Conditions
Sternoclavicular Joint Laxity or Pain
The sternoclavicular (SC) joint connects your collarbone to your breastbone. Hypermobility, micro-tears, or laxity from prior micro or macro-trauma in the supporting ligaments of this joint can cause localized clicking, popping, and a deep ache that spreads across the upper chest--often exacerbated by arm movement or sleeping on your side.
Pectoralis Minor Syndrome
The pectoralis minor muscle sits deep in your upper chest. Chronic tension, shortening, or scar tissue in this muscle can compress the neurovascular bundle traveling down your arm. This variation of Thoracic Outlet Syndrome (TOS) often presents as chest wall tightness, shoulder blade ache, and radiating numbness or tingling down the arm. Postural dysfunction, poor ergonomic set-up at your desk station, heavy phone/texting use, long drives, or any activity where your arms are suspended for prolonged periods without support are all risk factors for developing tension here over a period of time.
Pectoralis Major or Minor Strain/Tear
Acute injuries, repetitive heavy lifting, or sudden overexertion can cause micro-tearing within the large chest muscles. A strain can cause persistent, sharp chest wall pain that mimics heart or lunch distress-- particularly when you take a deep breath or push objects away from your chest. Participation in certain sports like volleyball, water polo, or those that involve repetitive throwing creates vulnerability for repetitive strain here.
Costochondritis
This condition involves inflammation of the cartilage that connects your ribs to your breastbone. It causes sharp, localized tenderness that can easily be mistaken for a heart attack. The pain is typically reproducible when pressing directly on the joints along your sternum. Risk factors include a recent move with a history of lifting heavy objects, a bout of upper respiratory infection leading to excessive coughing, or activities like rowing, paddleboarding, or surfing.
Mid-Trunk Pain & Thoracic Nerve Pathways
Intercostal Neuralgia
The intercostal nerves travel directly underneath each of your ribs. Irritation, compression, or inflammation of these nerves—whether from an old rib injury, shingles, or postural strain—results in a fiery, burning, or electric shock-like pain that wraps around the side of your chest or upper abdomen.
Intercostal Muscle Strain
The intercostal muscles sit between your ribs and help stabilize your chest wall during breathing and movement. A strain or micro-tear in these muscle fibers causes localized, sharp, or aching pain that can mimic heart or lung conditions. The pain is typically reproducible when pressing directly between the ribs or during sudden movements. Risk factors include explosive twisting motions, sudden heavy lifting, a violent bout of coughing, or overexertion during activities like tennis, golf, or heavy overhead training.
Referred Pain from Thoracic Radiculopathy
Spinal issues are not limited to the lower back or neck. A herniated disc with nerve root compression in the middle back (thoracic spine) can project sharp, radiating pain directed into your chest wall or abdominal area. Although it’s significantly less common to sustain a thoracic disc herniation with subsequent nerve impingement, it does happen and can manifest as chest pain in that nerve’s distribution.
Diaphragmatic Myofascial Strain or Spasm
The diaphragm is a large, dome-shaped muscle separating the chest cavity from the abdomen, anchoring directly along your lower internal rib cage. Just like any other muscle, it can sustain micro-tears, experience spasms, or develop hyperirritable myofascial trigger points from chronic muscle shortening (ie habitually sitting asymmetrically). This results in a deep, gripping upper abdominal pain that closely mimics gallbladder or stomach pathology. A key distinguishing feature is that the pain fluctuates directly with respiratory mechanics—intensifying during deep inhalations, yawning, sneezing, or when tensing the upper core. Risk factors include chronic chest-breathing habits, sudden blunt force trauma to the solar plexus, violent coughing or vomiting fits, or heavy powerlifting while holding your breath. Scoliosis typically impacts the thoracic spine and can create abnormal forces and torques in the muscles and organs that lie in front of the spine, including the diaphragm.
Abdominal & Core Wall Dysfunctions
ACNES (Anterior Cutaneous Nerve Entrapment Syndrome)
ACNES is an underdiagnosed nerve condition for which the small cutaneous branches of your intercostal nerves become trapped as they pass through the tough fibrous layers of your abdominal rectus muscles and fascia. It causes severe, localized abdominal wall pain that is easily confused with appendicitis, gallstones, or irritable bowel syndrome (IBS). A telltale sign is pain that intensifies when you tense your stomach muscles (a positive Carnett's test).
Abdominal Muscle Strain or Tear
A tear or strain within the rectus abdominis, obliques, or transversus abdominis can happen from coughing fits, intense core exercises, or improper lifting. It leaves behind localized tenderness, swelling, and pain whenever you sit up, twist, or attempt to stabilize your trunk. If the tear is lower down in the abs by their attachment on the pubic bone, the abdominal pain can be suprapubic in location. Sometimes people don’t even know they strained their abs and it’s the compensation they develop because of abdominal weakness that brings them to the doctor. For example, pelvic floor pain or adductor pain can occur because of these muscles’ over-firing to pick up the slack from the weakened abs. Rectus diastasis falls into this category and is not unusual in post-partum or post-menopausal women.
Sports Hernia (Athletic Pubalgia)
Despite the name, this is not a true hernia with a physical bulge. Instead, it is a strain or tear of the soft tissues (muscles, tendons, or ligaments) in the lower abdomen or groin area—frequently where the abdominal muscles meet the adductor tendons. It often causes deep, nagging lower abdominal pain that worsens during twisting, sprinting, or kicking motions. Engagement in recreational or competitive hockey, soccer, or basketball as well as any sport that involves cutting side to side is a risk factor.
Osteitis Pubis
This is a non-infectious inflammation of the pubic symphysis, the joint where your right and left pubic bones meet at the bottom of the pelvis. Due to the tight structural connection to the lower core, inflammation here can cause sharp or aching pain that radiates upward into the lower central abdomen and groin, mimicking bladder issues or lower GI pathology.
Pubic Symphysis Laxity
This is not uncommon in post-partum women, especially in those with hypermobility. The cartilage between the right and left pubic bones can weaken, and cause mechanical issues and inflammation. Pubic Symphysis pain can manifest as lower abdominal pain. There may be associated clicking or popping in the pubic region. If left untreated, the increased motion across the joint can lead to degenerative changes over time.
Downstream Obturator Internus Tightness Referring to the Abdomen
Your body's kinetic chain travels far. The obturator internus is a deep hip stabilizer muscle. When it develops chronic hypertonicity, spasm, or trigger points, it can cause severe referred pain that radiates upward into the lower abdominal quadrants and groin, masking itself as a bladder or digestive problem.
Get a Structural Assessment
If you are living with unexplained torso or abdominal pain and your organ workups have come back completely clear, your symptoms are very real—they simply belong to a different system. A comprehensive physical assessment evaluating your fascial networks, peripheral nerve pathways, and biomechanical alignment can finally expose the underlying structural source.
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