10 Body Mysteries Explained

YANNI TAN gets doctors to answer those inane, everyday questions you never thought to ask.

1. Why do I have earwax?
"It's an accumulation of dead skin, mixed with secretions from the external ear canal. The external ear canal is the body's only skin-lined 'cul-de-sac' and has a special mechanism to clear dead skin - skin migrates slowly out of the ear, carrying ear wax with it. It is only a problem if it blocks hearing. Using cotton buds to clear ears may impact the wax and cause infection, so allow nature to do its job or seek help from a doctor to clear the wax safely."
- Dr David Lau, consultant otolaryngologist, Singapore General Hospital

2. I sometimes feel my body jerk while sleeping. Why?
"Myoclonus - sudden, involuntary jerking of a muscle or group of muscles - is usually caused by sudden muscle contraction or by muscle relaxation."

"Few people are bothered or need treatment for the condition -many even sleep through it. However, those with more complex and disturbing sleep disorders, such as restless legs syndrome, may require treatment."
- Dr Charles Siow, consultant neurologist, National Neuroscience Institute

3. Why do I get a strange sensation when I hit my elbow?
"Inside your elbow, there is a bony protrusion called the medial epicondyle. Your ulnar nerve runs behind the medial epicondyle, and continues downwards to supply the inner part of your forearm, down to your fourth and fifth finger. If you flick the ulnar nerve against the medial epicondyle with your fingers, or if you knock the medial epicondyle against something hard, you'll stimulate your ulnar nerve, giving you that shooting sensation down to your fingers."
- Dr Benedict Tan, head and consultant sports physician, Changi Sports Medicine Centre

4. What causes hiccups?
"Hiccups are involuntary contractions of the diaphragm. As it contracts repeatedly, the opening between the vocal cords snap shut to check the inflow of air, causing hiccups. Although cancer, chest infections, heart attack, kidney failure or neck tumours may cause hiccups, there's often no clear reason."

"Consult a doctor if they become chronic and persistent (more than three hours), affect sleep or interfere with eating. Usually, encouraging carbon dioxide build-up in the blood (eg holding your breath) is sufficient to stop the hiccups."
- Dr Steven J Mesenas, consultant gastroenterologist, Singapore General Hospital

5. Why do I snore when I'm exhausted?
"During sleep, our muscles are relaxed and tissues at the back of the throat become floppy and can vibrate, causing snoring. Extreme tiredness and the intake of alcohol can reduce muscle tone making us more prone to snoring. Being overweight can accentuate the problem as there is more floppy fatty tissue that can collapse and vibrate. Snoring may be a health risk if it interferes with normal breathing during sleep."
- Dr David Lau

6. Why do I get stitches when I run?
"A popular theory is that stitches are caused by air trapped in the intestines. This may interfere with peristalsis - the bands of constriction that move down the gut, pushing the intestinal contents through - and explains why exercising after a heavy meal increases the chances of getting stitches."

"Another theory says that stitches are caused by spasms of the diaphragm caused, for example, by heavy breathing during exercise."
- Dr Benedict Tan

7. Why do I get the runs before an important presentation?
"The 'runs' - or excessive bowel movements - are a common symptom of anxiety. When we are anxious, the brain trigger the body to release several neurochemicals, such as adrenaline, which primes us for a 'fight or flight' response. These neurochemicals affect various organs, causing a faster heartbeat, quicker and shallower breathing and crampy sensations in our guts."

"Feeling nervous or anxious before stressful events is normal. Stress management techniques can help a person gain mastery over these symptoms."
- Dr Adrian Wang, consultant psychiatrist, Dr Adrian Wang Psychiatric & Conselling Centre

8. Why do my joints crack?
"The cracking sound is thought to be due to negative pressure in the joint when the joint is 'pulled' or bent. The joints are enclosed in a capsule and the negative pressure suddenly 'sucks' the capsule towards the centre of the joint, causing the cracking sound."

"Imagine sucking the air out of a plastic bottle - as the pressure in the bottle drop, the bottle will suddenly collapse inwards, creating a crushing sound. Habitual cracking may eventually caused accelerated wear and tear (as in the joints widening), but I doubt any studies prove this."
- Dr Benedict Tan

9. Why do I dream?
"No one really knows exactly why. It is likely that dreams reflect our thoughts, emotions and memories, so if you experience an intense emotional experience, you may dream about it. Some people look for hidden psychological meanings in dreams but there is no strong scientific proof or proven technique behind dream analysis. Other scientists believe that dreaming is how our brain releases emotional energy from our daily activities. In essence, dreams happen because our minds are still churning events in our brains while we sleep."
- Dr Adrian Wang

10. Why do I get goose bumps?
"Goose bumps develop when one is cold or frightened. They are actually hair follicles being elevated above the skin and this is brought about by contraction of the small muscles at the base of the hairs, in response to an external stimulus. When the hair stands on end, it traps air and forms a layer of insulation. However, this only applies to individuals who are hairy. It is therefore uncertain what the exact role of goose bumps is."
- Dr Cheong Wai Kwong, consultant dermatologist, Specialist Skin Clinic



Extracted from Simply Her / May 2006