In drug trials to test how effective pain relief is, toothache sufferers are often chosen as guinea pigs. That's because the teeth are full of nerves - and our body uses nerves to detect and send messages to the brain about pain.
Nerve pain is commonly accepted as one of the most excruciating things humans go through - it causes an intense, shooting or stabbing pain that stops you in your tracks.
Now, we literally couldn't live without our nerves; we need them to move, to feel, to digest and to breathe. But not all our nerves detect pain. Some nerves govern only movement - these are called 'motor nerves'. Some work without us having any control over them, governing our breathing and digestion, etc. These are called 'autonomic nerves'.
But others - the sensory nerves - deal mainly with sensation. When you bang your 'funny bone', the pain actually comes from pressure on the ulnar nerve in your arm, which carries sensation from your hands to your brain. We need these sensory nerves to stop us from damaging ourselves (imagine if you didn't notice when you put your hand on a hot stove). But when these nerves get inflamed or damaged, the pain can be intense.
Shingles is caused by infection with a virus called varicella zoster. Chickenpox is caused by the same virus. After you recover from chickenpox, the virus hangs around in the nerve roots next to your spine. It can lie dormant, causing no symptoms, for many years, before coming to life for no apparent reason and causing a painful, blistering rash over the part of skin supplied by that nerve root, just on one side of your body.
Most people recover completely from shingles. However, sometimes the inflammation in the nerve continues, causing 'neuralgia'. This persistent pain is more common if you catch shingles over the age of 60. Treating shingles with antiviral tablets may reduce the risk - but you need to start treatment as soon as possible after the rash occurs. You'll often get pain in a band around one side for two to three days before the rash appears. Your GP is unlikely to be able to make the diagnosis until you have a rash, but you might be able to book an appointment for a couple of days later, which you can cancel if the pain goes without any evidence of a rash.
This nerve pain affects the pain over the part of your face supplied by the trigeminal nerve. It can come on suddenly, and the pain can be brought on by chewing, touch or even wind blowing on your face. It's usually caused by a blood vessel pressing on the nerve as it emerges from the brain at the base of your skull. We don't know why this happens to some people and not others, but treatment is based on your symptoms, not the cause.
Proctalgia fugax - literally a pain in the bottom
The translation of this long medical term is pain (-algia) in the bottom (proct-) that's fleeting (fugax). It may affect one in six people. Caused by sudden spasm in the muscles around the bottom, it gives rise to really nasty shooting pain in the bottom that lasts from seconds to minutes.
Because the pain is very short-lived and tends to come in bouts just a few times a year, most people don't feel they need treatment. But it's definitely worth getting checked out, because very occasionally more serious problems like cancer around the bottom can cause similar symptoms (simple examination and blood test can usually rule this out). In severe cases, medicines can help.
Back pain is one of the most common kinds of pain - and by golly, it can hurt! About four in five people get back pain at some point in their lives, and it can strike at any age - in fact, it's one of the most common causes of working people going off sick in the UK.
All the main nerves supplying the body are carried in the spinal cord inside your spine. Very severe pain that goes down to your leg, or causes weakness/numbness/tingling in your leg, may be due to the nerve root being squashed or irritated.
Nerve pain treatments
Simple painkillers often don't work well for nerve pain. But these days there are lots of medicines which damp down the responses of your nerves, easing the pain. Many of these medicines were originally invented to treat other diseases of the nervous system - for instance, many epilepsy medicines and antidepressant tablets have been found to be effective for nerve pain.
These tablets can cause side effects like drowsiness. If they don't work, or if you can't tolerate the side effects, other treatments like local anaesthetic injections into the nerves may offer relief.
With thanks to 'My Weekly' magazine where this article was originally published.