The Hidden Facts Of Our Hands

23 November 2007
What your hands reveal about your health

Source: www.bbc.co.uk

I always try to shake hands when I meet a patient for the first time. I'm not just being polite - your hands are packed with information about your general health. In fact, doctors can often tell more about your health by your hands than your face.
From skin rashes and shakiness to the shape of your fingers and the state of your nails, your hands are a trail of red hot clues.
Handshakes and shaky hands
An innocent hand shake can often give doctors a clue as to how anxious you are - you might have unusually hot or sweaty palms. But this can also indicate an overactive thyroid or perhaps another type of gland problem.
GPs may not be consciously assessing your endocrine system as we greet you, but we’re likely to notice anything unusual.
At the same time, your doctor could be alert to any bony deformities or painful areas in your hand - though he or she will try not to make you wince with their grip. People with osteoarthritis often have hard bony lumps around the joints of their fingers, especially the joint nearest the fingertips. These are called Heberden’s nodes, named after the prominent 18th century English physician William Heberden.
It's thanks to another British physician that I might check for a particular type of tremor in your hands. James Parkinson documented the symptoms of Parkinson’s disease in 1817 in his Essay on the Shaking Palsy. The tremor of Parkinson's classically has a frequency of about 4-5Hz, is worse at rest, and improves on movement.
There are other tremors, too. An 'essential' tremor is more rapid and, if you've got warm moist palms, might get me thinking about your thyroid. On the other hand, it could be down to alcohol withdrawal if you’re alcoholic, or simply something you've inherited.
Why is he looking at my hands?
After a handshake and a check for any tremor, your GP may at some point later in the consultation take your hands and have a really good look at them because they contain important clues about your health and habits.
Tobacco stains are a giveaway - you may say you're not smoking any more, but your yellow-brown fingers can betray you.
Your hands can also tell your doctor a lot about the state of your liver. One of the classic signs of liver disease is reddening of the skin on your palms, typically the side where your little finger is, known as palmar erythema.
There are other causes and it doesn't always mean something's wrong, but sometimes it can point your GP in the right direction.
Another possible sign of liver disease is the spider naevus – a central capillary with several fine blood vessels running out from it, a bit like a spider's legs. They can occur anywhere on the skin but hands are a common site.
Lots of us have the odd spider naevus, but if you have many it's worth having them checked out. People with alcoholic liver disease often have both multiple spider naevi and palmar erythema.
Dupytren's contracture has become famous as a problem former prime minister Margaret Thatcher has developed. A thickening of the tissues in the palm of the hand slowly causes some of the fingers to bend over into the palm, forming a sort of claw. It typically affects the ring finger first.
Doctors don't yet know why this tissue becomes thickened. It seems to run in families, but it's more common in people with cirrhosis of the liver, diabetes, epilepsy and alcohol dependence.
One of the most striking things your doctor looks for is 'clubbing'. This is where the soft tissue around the ends of your fingers and toes increases, and your fingers end up looking like matchsticks with a sort of clubbed end.
Again, no one knows why it happens but it's associated with a range of conditions, from serious lung disease to liver cirrhosis or inflammatory bowel diseases.
Nails and health
Your nails can tell a fascinating story about your health - past and present.
The reason you're asked to remove any nail varnish when you're about to have an operation is that one of the easiest ways to check how much oxygen there is in your blood is by looking at your nails - they turn from a healthy pink to a dusky blue colour if you’re low on oxygen. Nail varnish could conceal an important clue to how you are.
Hollowed-out, spoon-shaped nails - known as koilonychia in the trade - can be normal in children and they grow out of it, but sometimes it can be a sign of iron deficiency.
Pitting of the nails - tiny depressions in the nail plate - is classically seen in psoriasis. But you can also get it in a variety of other strange-sounding diseases such as sarcoidosis and pemphigus.
Splinter haemorrhages are long, thin, vertical red or brown lines beneath the nail. They're caused by blood leaking from capillaries, often after the nail's been damaged, or because of psoriasis or a fungal infection.
They can sometimes be a sign of something called bacterial endocarditis - a serious infection of the heart valves.
Horizontal lines (depressions) across the nails, called Beau’s lines, can provide a fascinating history of trauma or illness. They rarely represent anything serious, but they're caused by any disease severe enough to disrupt nail growth.
Knowing that nails grow at a rate of 1mm every six to ten days, you can estimate the timing of the disease by measuring the distance from the line to the nail bed.
Children and healthy adults commonly have one or more white lines or spots on one or more nails. These can appear in different places on different nails, they don’t span the nail and are nothing to worry about. They’re thought to be due to random trauma to the nail bed.
All of which explains why your GP might take a close look at your hands.

Dr Graham Easton works in a London GP practice with around 10,000 patients. It has three GP partners, three salaried doctors and fully computerised medical records. His medical training was at The Royal London Hospital. He's also an experienced medical journalist who has worked for BBC Radio Science and the British Medical Journal.