Fun facts

Kay’s Kwestions: answers to your questions about the human body

If you're anything like us, you're probably bursting with questions about the human body! It is a fascinating (and gruesome) place after all. Luckily, former doctor Adam Kay has answered a myriad of questions in his guide Kay's Anatomy.

Adam Kay
An illustration of skeleton being x-rayed and looking down at the x-ray
Illustration: Henry Paker | Kay's Marvellous Medicine

Why do I get pins and needles?

Pins and needles is the name for a feeling like someone is jabbing your skin with pins and needles. One cause for this is that someone is actually jabbing your skin with pins and needles. More commonly, it happens when you sit in the same position for too long or lean on your arm for ages. If you put pressure on a nerve, it blocks the pathway between your brain and your foot or arm – you’ve essentially broken the Wi-Fi. Once you change position and the nerve can work again, it goes a bit haywire, causing pins and needles. Or paraesthesia, if you want to use its posh doctory name.

How much sleep do I need?

Someone your age generally needs between eight and ten hours of sleep. But everyone is different. Thomas Edison, who invented microphones, light bulbs and movie cameras, only slept for four hours a night – maybe he was too busy inventing stuff to have any time for napping. If you need some inspiration to get more Zzzzs, super-mega-genius Albert Einstein slept for ten hours a night.

Illustration of Thomas Edison in bed shielding his eyes from a lightbulb
Illustration: Henry Paker | Kay's Marvellous Medicine

What causes an ice cream headache?

Sometimes when you eat an ice cream or drink a really cold drink, you might get ‘brain freeze’ – a short, sharp, horrible headache that can really spoil your chocolate-chip cookie-dough raspberry-ripple supreme with multicoloured sprinkles and pieces of walnut. (Please check that you’re actually eating pieces of walnut, and not pieces of cerebellum.) You’ll be relieved to hear that it’s not actually your brain freezing. It’s because your nerves have got muddled and sent pain signals to your brain by accident when they were sensing cold temperatures. Stupid nerves.

Why do some people need wheelchairs?

There are lots of reasons why people get around using wheels instead of feet – for example, they might have had an injury to their spinal cord that means the nerves can’t travel down to their feet, so the brain’s messages can’t get through. Or they could have been born with a condition that affects their muscles (such as muscular dystrophy) or their nerves (such as cerebral palsy). They can go to school like everybody else, and when they’re older they can go to work and drive cars – everything really!

Listen to an exclusive extract from the Kay's Anatomy audiobook

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