Up to 460,000 Australians have preventable headaches that are caused by taking too many painkillers, according to doctors.
People are caught in a loop of "medication overuse", which gives them more headaches.
Some studies say two percent of the world's population suffer from medication overuse headaches, but the World Health Organisation says it could be closer to five percent.
Associate Professor Richard Stark, a neurologist at the Alfred Hospital in Melbourne, told ninemsn that people should limit their consumption of simple analgesics, such as paracetemol and anti-inflamatories, to 15 days a month. Codeine and triptans should be taken no more than 10 days a month.
"Codeine is probably the one that is most troublesome in Australia — it's available over-the-counter," Professor Stark said.
"People who start using codeine on a daily basis do get into this loop of medication overuse. The body is expecting there to be codeine floating around and as soon as the level dips, they get a headache breaking through. The best way to deal with that in the short term is to take more codeine, but of course that perpetuates the cycle."
It's usually people with chronic migraines who get trapped in the medication cycle, but Professor Stark says stopping the medication will help them in the long term.
"It is a matter of being prepared for a week or two to deal with headaches in some other way," Professor Stark said.
"But they need to understand that if they can get through a couple of weeks with difficult headaches without using codeine that things will get better and their headaches will become substantially easier to manage."
But Professor Stark was quick to point out that medication-overuse is only an issue with painkillers, not preventative medication.
"There are a whole set of preventive medications that can be used on a daily basis," he said.
"It's important to distinguish between those medications where the aim is to take them every day to prevent headaches coming on, as opposed to the painkiller medication where you take them when the pain comes on. Don't rely too much on painkillers all the time, but rely on preventive medications."
Professor Stark recommends people suffering migraines deal with them as quickly and effectively as possible.
"The most sensible way of dealing with migraine is to try to treat it aggressively when it occurs and get rid of it — hopefully by doing that, it won't come back the next day and the day after."
The UK government has just released guidelines for treating headaches, which are based on the International Headache Society classifications that Australian neurologists already follow.