both hyperventilate and hold their breath. The structures in their brain
stems that protect against suffocation by monitoring the carbon dioxide
level of the blood may be overly sensitive, causing extreme corrections in
their breathing rate.
As you learned in the last chapter when you tried it yourself, too
much breathing causes all sorts of weird sensations. When you hyper-
ventilate, it decreases the carbon dioxide level in the blood, which raises
alkalinity, which increases the excitability of peripheral nerve endings,
causing tingling around the mouth, fingers, and toes. The high alkalinity
also decreases blood flow to the brain, which can make you feel dizzy and
strangely separate from your body.
SHORTNESS OF BREATH. The problem here is not too little oxygen, but
too much carbon dioxide. Rapid, shallow breathing and tension in the chest
muscles makes it easy to get air in but hard to get it out. This makes the
breath-holding and hyperventilating problem worse. Suffocation sensors in
the brain stem detect too much carbon dioxide and misread it as a need for
oxygen. This causes more hyperventilation, which escalates the cycle further.
A common home remedy for hyperventilation used to be having a
person breathe into a paper bag to increase blood carbon dioxide level.
Don’t try this at home, because it makes the situation worse. Exercise
works far better to regulate breathing.
MUSCULOSKELETAL PAIN. Sudden tightening of the muscles hurts,
especially if you aren’t using them to defend yourself or escape. By itself,
muscle tightening can cause excruciating headaches or backaches, or can
intensify old injuries, but that’s not the half of it. Think of the physics
involved—the body is expanding from the inside, but squeezing down into
a cringe outside. Blood-engorged muscles take up more space, which can
pinch nerves, scrunch organs, and cut off circulation, all of which can
cause numbness or referredpain. This is pain felt at a different location
than the actual blockage. A pinched nerve in the shoulders may cause pain
in the chest. Everything in the body is connected to everything else.
DIZZINESS AND FAINTNESS. The change from the resting state to action
occurs so fast it can make your head spin. Actually, it’s the decreased blood
flow to the brain caused by the increased alkalinity brought about by
hyperventilation that makes people dizzy, and it causes the weird sensations
76 ❧Explosions into Fear