Most of us have had a headache at some time, although it is their intensity and frequency that marks the boundary between typical sporadic pain which sometimes occurs and a chronic problem.

"We consider headaches to be relatively frequent when they occur more than four times a month," said Pablo Irimia, a neurologist and the coordinator of the headaches study group of the Spanish Neurology Society (SEN).

"Is there a remedy for a headache, apart from taking ibuprofen or paracetamol?" I asked him. "The important thing is to relax, rest and even take a walk," he said.

That was an unexpected answer; so, while it seems wrong to contradict a specialist, I persisted: my headaches don't go away unless I take a tablet, and when I have a headache I don't feel like going for a walk, I told him. I feel better if I stop what I'm doing and lie down for a while.

I was surprised by his last answer, but this one came as a shock. "That's because you don't have a tension headache," he said. "What you have is a migraine."

That was worrying, because I have always thought that migraine is something much worse than a headache. But he rushed to explain: "The most common type is what we call tension headache. But, when a migraine is slight, the difference between the two is quite subtle and they can be confused with each other," he said.

And yet they have little to do with each other, neither in prevalence - the World Health Organisation calculates that 70 per cent of the population suffers from occasional tension headaches and for between one and three per cent of them they are chronic, while migraines affect 12 per cent of the population - nor in remedy.

"A tension headache is less debilitating and in fact, most people who suffer from them feel better if they go for a walk or do some exercise. In the case of migraines, although they may be low in intensity, what people want to do is stay still, in silence, and lie down," explained Dr Irimia.

So, here are some ways of knowing which type we are suffering from and what we can do to ease the pain.

When to take painkillers

Do you take an ibuprofen but the headache doesn't go away? Then maybe that isn't what you need.

"A tension headache is usually mild and improves when you rest, without the need for analgesics. Migraine usually does need medication, and ibuprofen is better than paracetamol because it is anti-inflammatory," said Dr Irimia. But, he added, be careful about what you take because if it is not administered correctly it can cause a headache, specifically a rebound headache, which the WHO website says is caused by chronic and excessive consumption of medication to combat headaches.

With regard to medication for preventive purposes, Dr Irimia said it is better to take the painkiller at the start, rather than wait for it to get worse. "In the case of women who have a migraine when they menstruate, for example, it can be useful to take the anti-inflammatory a day beforehand," he said.

A walk or a lie-down?

You may feel like one more than the other, depending on the type of pain. Although rest improves both types, going out for some fresh air can relieve a tension headache or, at least, will stop it getting worse. Migraine, on the other hand, no matter how incipient it may be, demands a rest.

"It can be accompanied by sensitivity to noise or light, and it is not unusual for someone with a migraine to have nausea or even vomiting," said Dr Irimia, and those symptoms do not occur in the other type of headache.

What about sleep? Can that get rid of a headache? "For tension headaches, sleep is very effective. In fact, people who suffer from them frequently are often early risers. They feel worse as the day goes on, and then get a headache in the evening," he explained.

Does all the head hurt, or just one part?

The WHO describes tension headache as being a band of pressure or oppression around the head, which sometimes radiates to the neck, or starts there. Dr Irimia said there are two causes for this type of pain. "A muscular insufficiency in the neck, which becomes contracted with different postures. Or an accumulation of stress and tiredness which also induces muscular contraction in the neck," he said. However, if the pain is only in one part of the head, it is probably a migraine.

There are also striking differences in the way people who are affected describe how they feel. "In the case of headaches it is like a type of pressure around the whole head, but migraines are like pulsation or throbbing," he said.