The human body can be mysterious. You know that your heart beats to circulate your blood, and that sweating on a hot day cools your body. But why do you hiccup, get goose bumps, or develop an ice cream headache? Does being scared really make the hair on the back of your neck stand up? What is your body trying to tell you when your foot falls asleep or you get a charley horse? Most of these mysterious body quirks do have logical explanations.
Is It a Sneeze or a Fastball?
You may have never heard the medical term for sneezing: sternutation. A sneeze may start in your nose, but it requires a lot of cooperation from other parts of your body. Your nose sends a message to a special part of your brain to trigger the sneeze (your body's way of getting rid of an irritant in the nose), which requires a quick response from muscles in your chest, belly, throat, and even your eyes. Yes, it's true you always close your eyes when you sneeze. A sneeze is so effective that it can send irritating particles out of your nose at a speed of about 100 miles per hour.
A Cup of Water for Your Hiccups
Researchers know how the body makes hiccups, but they don’t always know why. Unlike sneezes, hiccups offer no obvious benefit. A hiccup occurs when a big abdominal muscle called the diaphragm is irritated. It contracts suddenly, sucking air into your windpipe. In some cases, hiccups can last so long that they require medical treatment. Many of the home remedies your mom prescribed to stop hiccups actually do work, including holding your breath, drinking cold water, and eating a spoonful of sugar. Possible hiccup triggers include anxiety, drinking a carbonated beverage, and eating hot, cold, or spicy food.
Saying Whoa to a Charley Horse or Cramp
Charley horse is a slang term for a muscle cramp, usually in a thigh or calf. Cramps typically occur in muscles that stretch between two joints in your body and are common in the lower legs, feet, arms, hands, and stomach. Although there is no hard evidence that you will get a charley horse if you swim after eating, there is some common sense behind your mom's old warning: After you eat, blood rushes to your stomach, and one known cause of cramping is not getting enough blood to your muscles. The best way to get rid of a painful charley horse or other muscle cramp is to stretch and massage the muscle.
Defrosting the Ice-Cream Brain Freeze
It's a hot summer day, you just took a big lick of ice cream or a big gulp from a cold drink, and suddenly your forehead and temples hurt like heck. Don't worry — you haven't frozen any brain cells. A so-called brain freeze, or ice cream headache, occurs when cold food or drink touches nerves in the roof of your mouth, which then stimulates blood vessels in your head to suddenly swell and cause your head to ache. The pain doesn't last long or do any damage to your brain or any other part of your body.
Open Your Eyes to the Cause of Spasms
In the movies, a twitching eye is a dead giveaway of a shady character, but in real life involuntary blinking or spasm of the eyelids, called blepharospasm, is caused by an abnormal nerve function. People who have twitching of the eye may also be tired, tense, or sensitive to bright lights. In severe cases in which the twitching does not go away, treatment can include injection of Botox (botulinum toxin) into the muscles around the eyes.
Nothing Funny About the Funny Bone
Someone with a good sense of humor may have a funny bone that is easily tickled, but if you have ever banged your elbow, the numbing, tingling sensation you get in your lower arm and hand is not at all amusing. However there is no such thing as a funny bone in the body. That strange sensation results not from hitting a bone but a nerve — the ulnar nerve that runs over the inside end of the long bone in your upper arm. The ulnar nerve helps you move your hand and supplies feeling to your last two fingers. A little bump feels strange, but does no harm.
When a Foot or Leg Falls Asleep
Most people think the tingling that happens when a body part “falls asleep” comes from cutting off the circulation, but it is usually due to putting too much pressure on a nerve. In most cases the body part — typically the legs, feet, arms, and hands — will "wake up" as soon as you change position and relieve the pressure. The medical term for those pins and needles you feel is parestheisia. Paresthesias that keep coming back, or don't go away, could be a sign of a neurological problem and need to be investigated.
When Your Body 'Falls' During a Dream
Have you ever had the feeling of your body falling through space shortly after you fall asleep? Don't worry — you won't die if you hit the ground in a dream, as urban legend speculates. This feeling of falling is a common sleep sensation known as a hypnagogic hallucination. These sleep hallucinations include sensations like falling, being touched, paralysis, hearing voices, or seeing strangers in your room. Sleep hallucinations are more common in children and usually occur soon after falling asleep. Although severe and persistent hallucinations may be a sign of a sleep disorder, most night terrors decrease with age.
Floaters and Flashes Before Your Eyes
It's common to see dots, circles, clouds, or small squiggly lines that seem to float in front of your eyes. Actually, they are inside your eyes. Floaters are caused by tiny clumps that form in the jelly-like substance in your eyeballs called the vitreous gel. What you are seeing is the shadow these particles cast on the back of your eye, where the nerves for sight are located. Flashes — also referred to as seeing stars — are caused by the pull of the vitreous gel on the back of your eye. Floaters and flashes increase with age and are generally not harmful. But a sudden increase in the number of floaters and light flashes accompanied by vision loss could indicate that you have a retinal detachment — a serious medical emergency.
Frightful Body Chills and Goose Bumps
A good scare really can give you goose bumps and raise the hair on the back of your neck. Goose bumps can be caused by strong emotions like fear or by exposure to cold. Your body produces the bumps by contracting the muscles around your hair follicles, pulling the hairs into an upright position. Chills that result from exposure to cold or a fever also cause goose bumps, but you can get them without having chills. Another cause of chills and goose flesh is withdrawal from certain drugs, which is where the term "going cold turkey" comes from. The medical word for goose bumps is horripilation.