Bodily Oddities

Referred pain

Also called: Reflective pain

Pain from an internal organ often shows up somewhere else, like the left arm during a heart attack or the shoulder blade from a gallbladder. The nerves from the organ and from that patch of skin share a line into the spinal cord.

Nerves Reflex

How common

Everyone The basic wiring is similar in all people. Whether you feel it depends on what is wrong inside.

Does this happen to you?

How it works

Your skin is mapped in detail in the brain. Touch your fingertip and you know exactly where it is. Your internal organs are not mapped that way. The nerves from them enter the spinal cord at the same places as nerves from the skin1.

Scientists do not agree on the cause1. One of the oldest explanations is called convergence-projection. Pain fibres from an organ and from a patch of skin often end on the same neuron in the spinal cord. That neuron sends one signal up to the brain. The brain cannot tell which of the two sent the signal. It places the pain on the skin1. The patch of skin is set by which segment of the spinal cord the organ connects to, and that is the same in almost everyone.

How common it is

The classic patterns are1:

  • Heart attack: left arm, jaw, shoulder, neck, or upper back4.
  • Gallbladder: the tip of the right shoulder blade.
  • Appendicitis: first around the navel, then the lower right belly5.
  • Kidney stones: pain travelling from the flank down to the groin6.
  • Irritated diaphragm: the tip of the shoulder. This is Kehr’s sign2.
  • Brain freeze: the forehead, from cold on the roof of the mouth3.

The diaphragm and the shoulder are linked because the phrenic nerve, which serves the diaphragm, enters the spinal cord in the neck, next to the nerves for the shoulder2.

Is it a problem?

Referred pain is a normal feature of the nervous system. It matters because it can hide the true source. Doctors are trained to ask about the shoulder blade when they suspect the gallbladder.

The heart pattern is the one to know.

Call emergency services if chest pressure spreads to the arm, jaw, or back, and comes with:

  • sweating,
  • shortness of breath,
  • nausea.

Do not wait to see if it passes.

Sources and further material

  1. Wikipedia Referred pain
  2. Wikipedia Kehr's sign Shoulder-tip pain from irritation of the diaphragm.
  3. Wikipedia Cold-stimulus headache Brain freeze is referred pain from the roof of the mouth to the forehead.
  4. Wikipedia Myocardial infarction Describes the classic spread of heart attack pain to the arm and jaw.
  5. Wikipedia Appendicitis Pain starts around the navel and moves to the lower right belly.
  6. Wikipedia Kidney stone disease Pain from a blocked ureter spreads from the flank to the groin.

Updated , first published .

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Nerves Involuntary

Brain freeze

A short, sharp headache in the forehead a few seconds after cold food or drink touches the roof of the mouth. It usually passes in under a minute.

About 40–50% of people
Nerves Involuntary

Precordial catch syndrome

A sudden, sharp, stabbing pain near the heart that lasts seconds to a few minutes and gets worse when you breathe in. Doctors count it among the most common causes of chest pain in children and teenagers, and it is harmless.

80–90% of chest pain in young people, once injury is ruled out
Nerves Involuntary

Pins and needles

The prickling, buzzing feeling in a limb after you sit on it or lean on it. It happens when blood returns to a squeezed nerve and its sensory fibres briefly fire on their own.

Everyone
Brain Involuntary

Phantom phone vibrations

You feel your phone buzz in your pocket, check it, and nothing happened. Most phone users get this. The cause is not known. The brain may misread ordinary sensations as a buzz.

30–89% of phone users