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 DrThng.

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 DrPang.

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.

This article was first published in Mind Your Body, The Straits Times.

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The quirky body: Part 2