What makes pain non-mechanical

Mechanical spinal pain has a relationship with position and movement. Something makes it worse, something makes it better, and there is a posture that gives relief. That relationship is the single most useful screening question in the whole examination.

Visceral pain does not behave that way. It is present regardless of position, it may come in waves, it is often accompanied by systemic features, and no amount of shifting in the chair changes it.

The quieter impostors

• Gallbladder disease — right upper abdomen and right shoulder blade, worse after fatty meals.
• Pancreatitis — upper abdominal pain boring straight through to the mid back, often eased by leaning forward.
• Endometriosis — cyclical low back and pelvic pain tracking the menstrual cycle. Frequently dismissed for years.
• Abdominal aortic aneurysm — deep constant back pain, sometimes with a pulsatile abdominal sensation, in older patients with vascular risk.
• Shingles, before the rash appears — burning in a band on one side that does not cross the midline.

How we screen for this

Every intake here asks the position question, asks about fever, weight loss and urinary change, and asks what a patient’s other doctors are already treating them for. That is not thoroughness for its own sake; it is the cheapest way to avoid spending three months injecting a spine that was never the problem.

Where the story does not fit a mechanical pattern, we say so and route it, rather than treating the region that happens to be our specialty. Where it does fit, we get on with finding which structure.

Common questions

How do I know if it is my kidney?

Kidney pain typically sits higher and more to the side than lumbar pain, comes in waves rather than tracking movement, and often brings urinary symptoms, fever or nausea. It is not relieved by lying still.

The mechanism is covered in Pain on one side only is a narrower problem than pain across the whole back..

Can constipation cause back pain?

It can produce genuine referred low back discomfort, and it is worth resolving before concluding anything about the spine.

The mechanism is covered in Pain in the middle of your back, not the lower back.

My pain is worse after eating. Is that my back?

Very unlikely. A relationship with meals points to the digestive tract and deserves that workup instead. Visceral referral is a real consideration higher up the spine.

Related reading

• When back pain is an emergency
• One-sided low back pain
• Back pain at night
• What happens at the first visit

Where the threshold for investigating mid-back pain is genuinely lower.