May 28, 2009
Quirky body - Cover story
The quirky body
A door creaks at midnight. You are alone at home and it gives you goosebumps. You take a long dip in the bathtub and your skin becomes wrinkled. You hit your elbow hard against something and feel like electric currents are running up your 'funny bone'. These and other body quirks like twitching eyelids, side stitches and ringing in the ears are familiar sensations. MIND YOUR BODY asks doctors what lies behind 10 of these quirky occurences and whether they affect your health in any way
By Poon Chian Hui
1: Pins and needles
The feeling of prickly numbness in our limbs, usually called 'pins and needles', is a spontaneous sensation that is usually caused by temporary nerve compression, said Dr Josiah Chai, consultant neurologist at the National Neuroscience Institute.
When nerves are compressed, such as when one sits cross-legged for too long, sensory stimuli to the brain are blocked, triggering this body quirk. Doctors refer to it as 'paresthesia'.
It is usually nothing to worry about but prolonged occurrence could signal underlying problems.
'Transient symptoms associated with abnormal posture or position of limbs are usually not a concern. However, persistent and severe paresthesia, especially when it involves limb weakness, may suggest a more serious medical problem,' said Dr Chai.
It could indicate nerve disorders. Also, some diseases like diabetes and vitamin B12 deficiency can affect the nervous system, Dr Chai added.
It would be best to consult a doctor if this happens to you too frequently and if you experience weakness in the limbs at the same time.
2: Goosebumps
The term describes how our hair follicles stand out - usually due to anxiety or fear - in a way that they resemble the puckered skin of a plucked goose.
Goosebumps are a result of a reflex action called piloerection. Hair is lifted up and this causes the hair follicle to stand out, said DrSteven Thng, consultant dermatologist at the National Skin Centre.
This reaction is usually harmless and will fade away when the fear or anxiety subsides.
However, if the goosebumps do not go away, reasons other than piloerection have to be looked into.
'There might be other causes like blocked hair follicles, common in eczema patients,' said Dr Thng.
As blocked hair follicles may lead to further inflammation, a visit to a dermatologist would be a good idea if you have such skin inflammation conditions and constantly puckered skin.
3: Ringing in the ears
Tinnitus is the name for noises that we hear when an external sound is absent, said Dr Pang Yoke Teen, an ear, nose and throat specialist and the medical director of the Centre for Ear Nose Throat Allergy and Snoring at Paragon Medical Centre.
The ringing sounds are most commonly heard after protracted exposure to loud noise, like construction drilling and loud music.
'The sound can vary in pitch from a low roar to a high whine,' said Dr Pang. 'You may hear it in one or both ears and the effect can be temporary or permanent.'
About one in five adults would have experienced tinnitus at some point in his life.
The ringing sound is caused by damage to the inner ear hair cells, which detect sound.
While this injury can recover on its own - healing may take minutes to days, depending on the noise exposure - continual ear trauma can lead to hearing loss or permanent tinnitus.
Among the young, common causes of tinnitus are exposure to loud music at concerts or through earphones, said Dr Pang.
A study by British researchers found that 73per cent of rock music concert-goers reported tinnitus, while 66 per cent of clubbers and 17 per cent of stereo users also reported hearing difficulties.
However, permanent tinnitus can be overcome with the help of sound therapy and counselling. Some hospitals, like Changi General Hospital, have tinnitus counsellors who dispense advice on how to cope with this condition, which can be emotionally draining on the sufferer.
4: Wrinkly skin on fingers and toes after long exposure to water
People who go swimming, take long baths or do the laundry will know what wrinkly skin looks like. It is actually caused by absorption of water, said Dr Chai.
'Our padded fingers and toes soak up water like a sponge. The top layer of skin is more porous than underlying layers, so it absorbs water better,' he said.
The reason our fingers and toes do not swell like balloons but instead shrivel up like raisins is due to the attachment of the outer skin layer to underlying layers.
'The top layer of skin does not detach from our fingers, so the only thing it can do is wrinkle up to accommodate the increase in surface area,' said Dr Chai.
The effect is temporary and harmless. Skin will quickly return to normal when the excess water evaporates.
5: Eyelid twitching
The involuntary contraction of eyelid muscles can happen to people of all ages, especially those above 60 years old. It is mostly harmless.
'Eyelid twitching is almost always temporary and relatively harmless,' said Dr Ho Su Ling, a consultant ophthalmologist at Tan Tock Seng Hospital.
Some common causes are lack of sleep, stress and having had too much caffeine or alcohol.
'Occasionally, lid twitching can be triggered by dry eyes, exposure of the eye to wind or bright light or ingrown eyelashes,' said DrHo, who added that eye drops can be of help.
A simple solution is to get enough rest: more sleep has been shown to improve the condition in up to 75 per cent of sufferers.
However, if the twitching gets more frequent, becomes more vigorous and begins to hinder vision, medical help should be sought. It may signal a rare nerve irritation, said Dr Ho.
6: Seeing halos
Do you see ghostly halos around lights when you look at street lamps or vehicle headlights at night?
This halo effect is due to the irregular scattering of light rays, said Dr Ho.
Three parts of the eye come into play - the pupil, cornea and lens.
This phenomenon is partly related to large pupil size in dim light, said Dr Ho. The pupil controls the amount of light entering the eye and it enlarges when it is dark at night to allow more light in. This causes light to appear diffused.
The cornea helps to focus light that enters the eye. Hence, cornea-related problems like astigmatism result in poor focusing of light.
In some people whose pupils tend to dilate more, laser refractive surgery (Lasik) may cause an increased scattering of light when light goes through the operated part of the cornea.
Lens-related factors include cataract, which is the clouding of the lens - a structure that focuses light rays onto the retina. Artificial lenses that replace the clouded ones in cataract surgery may also cause glare in minority of people.
The condition is not serious unless there is severe pain, headache or nausea - these symptoms indicate the possibility of glaucoma, which can lead to blindness, said Dr Ho.
See an ophthalmologist if the halos hinder safe driving or seeing objects at night, she added.
7: Tearing when cutting onions
Unlike emotional crying, tearing up when one cuts onions has a practical, mechanical purpose. It washes away irritants in the eye.
'When an onion is cut, a volatile vapour that contains sulphur is released,' said Dr Ho. 'As the vapour wafts towards your eyes, it reacts with the water on the eye surface to form sulphuric acid.'
The acid burns and irritates the eye, so tears are released to flush it out, she said.
She advises against prolonged exposure, as it causes superficial erosion of the eye surface. Instead, try running a fan and wearing goggles when cutting onions or submerging them in water while cutting them, she said.
8: Side stitch
When you do sports like running and swimming, you may experience discomforting pain in your abdomen that ranges from a dull ache to an intense, stabbing pain. This is what we commonly call a side stitch.
Doctors call it an Exercise-Related Transient Abdominal Pain (ETAP), said Dr Ng Chung Sien, a sports medicine specialist at Changi General Hospital.
'ETAP is defined as a localised pain that may occur in any region of the abdomen during exercise,' he said. 'It is most commonly located just below the rib cage on the right side of the abdomen.'
What causes a side stitch is unclear. It could be due to the stretching of ligaments during exercise or an irritation of the abdominal wall lining due to friction caused by movement, said Dr Ng.
There is little to worry about if the pain subsides after exercise. However, if the pain persists, one should consult a doctor.
Otherwise, some useful tips to note are to increase exercise intensity gradually and to avoid eating large amounts of carbohydrate-rich foods an hour or two before activity, he advised.
That is because these foods can expand the stomach and irritate the inner abdominal wall, hence increasing the likelihood of stitches, he said.
9: Cold sweat
This condition is usually associated with anxious moments. When a person breaks out in cold sweat, he is perspiring but feels cold - which is strange because one sweats in warm temperatures. The perspiration is not actually cooler than normal though.
It is all due to perception, said DrNg. 'When we are anxious, there is a sudden release of adrenaline, which causes sweating,' he said. 'Adrenaline also causes blood vessels to shut down slightly, causing a person to feel cold.'
Other than anxiety, cold sweats can be caused by viral infections, malaria, tuberculosis and some types of blood cancer, said Dr Ng.
Cold sweats may also occur during emergencies such as a heart attack.
To be on the safe side, see a doctor if you get a cold sweat that is not related to a moment of anxiety. Causes are many and some are serious - like heart problems and immune disorders.
10: Funny bone
When you hit the back of your elbow, you may get a sharp, tingly shock. It is commonly called hitting your funny bone.
In fact, this is not a bone at all but a nerve that lies in the bony groove of the elbow joint.
'The sensation is the result of direct compression of the ulnar nerve at the elbow,' said Dr Peng Yeong Pin, head of the department of hand and reconstructive microsurgery at the National University Hospital. 'This type of nerve compression is known as the cubital tunnel syndrome.'
So why do we not feel such shocks when other parts of the body are hit?
'The ulnar nerve is not protected by muscles,' explained Dr Peng. 'When this part gets knocked accidentally, there will be a direct impact on the nerve, resulting in the tingly and painful response.'
Here is something that is not so funny: You should not keep hitting the nerve just for the thrill of it. Chronic tension or repeated irritation of the nerve will result in nerve damage that can be irreversible, he warned.
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