Control Pain & Heal Faster with Your Brain

KEYPOINTS

• 01

  Pain and tissue damage can be completely separated

  Neuroscientists prefer the term 'nociception' because pain is subjective. Radiation and excessive X-rays can damage tissue with no sensation at all, while a man in a British medical case report was in agony after a 14-inch nail went through his boot, only for doctors to find it had passed between his toes without breaking the skin. Seeing the nail produced a specific, nail-like pain.

• 02

  Receptor density shapes both sensitivity and healing

  Areas packed with receptors, such as the fingertips and lips, have more 'pixels' in the brain's body map, the homunculus. They also have more blood vessels and glia to drive inflammation. As a rule of thumb, large, low-sensitivity areas hurt less when injured but tend to heal more slowly because fewer cells are nearby to mount repair.

• 03

  Some pain is necessary, and acute inflammation is good

  People born with mutations that prevent them from sensing pain never trigger the inflammatory response, and their joints literally disintegrate. Huberman's main message is that acute inflammation is the tissue-repair response that calls in cells to clear an injury. Only chronic, out-of-control inflammation is the problem.

• 04

  The brain can relieve pain from the top down

  Phantom limb pain arises because the brain's map of the missing limb is intact but has no proprioceptive feedback, so it ramps up activity. V.S. Ramachandran's mirror box let amputees 'see' the missing limb move into a comfortable position, giving immediate relief and remapping. The brain adapts to whatever input it receives, as cochlear implants also show.

• 05

  Use the injured side and restrict the healthy one

  Much of the atrophy after a cast comes from inactive nerves rather than unused muscle. About a dozen papers from Timothy Schallert's lab (with Theresa Jones and others) in the 1990s–2000s showed that after one-sided brain or limb damage, restricting the healthy limb forces use of the injured one. This produced plasticity on both sides of the brain via the corpus callosum and faster recovery, provided the injured side is used without pain or further harm.

• 06

  For brain injury, avoid a second hit and support the glymphatic system

  Concussion and TBI symptoms include headaches, light sensitivity, poor sleep, poor concentration and mood changes. The agreed priority is to avoid another TBI. The glymphatic system, the brain's 'sewage' clearance, works mostly during slow-wave sleep early in the night. Sleeping on your side, or with the feet slightly elevated, appears to increase clearance (limited but solid data); Huberman puts a thin pillow under his ankles.

• 07

  Zone 2 cardio supports brain clearance

  A review he cites found that conversational-pace cardio for 30–45 minutes three times a week improved clearance of debris after injury and glymphatic flow generally. Clear it with your physician if you are injured. He contrasts this with the popular focus on high-intensity intervals.

• 08

  Belief, adrenaline and love all blunt pain

  Punches barely hurt during a fight because adrenaline and noradrenaline shut down pain pathways; it hurts afterwards. People expecting morphine report relief before receiving it. Sean Mackey's Stanford imaging study found that looking at a romantic partner's photo raised heat-pain thresholds, and the effect was stronger the newer and more obsessive the love. Huberman thinks dopamine is the likely driver, though it hasn't been measured.

• 09

  Acupuncture effects depend on where and how hard you stimulate

  Qiufu Ma's lab at Harvard found that weak stimulation of the abdomen did nothing, while intense electroacupuncture there was pro-inflammatory via a splenic sympathetic pathway. Low-intensity stimulation of the hind limbs activated the vagus nerve and lowered inflammatory markers such as IL-6. So acupuncture can't simply be called good or bad; it maps onto real body–autonomic wiring.