I wrote this for Harvard's PROJAK newsletter in response to the theme: Describe a superstitious belief that you follow, or somehow affected your life.
In the West, when we have a runny nose, a cough, a headache, congested sinuses, a sore throat, frequent sneezing, a fever, general weakness or any combination of the above we say we have "a cold." Our persitent use of "cold" is a historical anachronism from the days before germ (and virus) theory of medicine where we thought that "colds" were caused by being generally cold and wet. They can be co-incident (e.g. being cold and wet can supress your immune system to the point where a cold virus can gain a solid foothold), but that does not necessarily mean there is a causal relationship (i.e. in the absence of a rhinovirus, you're not going to get a "cold").
In Indonesia, people refer to one with the abovementioned list of symptoms as having "masuk angin." Literally this means "wind has entered." In addition to the list of symptoms that accompany a "cold", Indonesian "masuk angin" sufferers can expect to burp and, less frequently, may even have an upset stomach, with all its concomitant symptoms. The burping and/or farting is key, as it symbolises the "wind" trying to escape.
You can catch "masuk angin" by being exposed to wind or any sort of fast moving air. Common ways that this can happen include being in the direct airstream of a fan or air-conditioning unit, having your window open in a moving car, sitting on a motorbike without a jacket, being outside on a windy day and so on. While some expatriates in Indonesia like to make fun of the locals for this superstition, of course, this is no more ridiculous than people warning "you'll catch your death of cold" in the West.
Good ways to get rid of wind include eating foods or drinking tonics that are "heating", ("heating" being foods defined thusly by Chinese medicine, such as ginger, etc.) and getting massaged. There are various massage techniques to draw out wind - the most notable of which, "kerok," involves rubbing the skin with a coin until you have big red lines all over your body - but during all of them you (and your masseur) are expected to burp profusely as the wind is drawn out of your body.
Now, being the sceptical sort of chap that I am, I try not to buy in to either superstition. But being used to the Western concept of "having a cold," the idea that you burped when you had acute viral rhinopharyngitis seemed odd to me. I expressed my scepticism to Indonesian friends who just shrugged the sort of shrug that says "I don't care if you don't believe me, it's true."
Sure enough, the next time I got a cold, I became very aware of my burping. "Do I always burp this much?" "Was that a 'masuk angin' burp or an 'I ate my food too fast' burp?"
Sceptical folk like me are often very quick to dismiss traditions that seem to be based on superstitions. We often mistake "all we currently know" for "all we can know." There is some bullshit behind the Western conception of "catching a cold," but there is some useful practical advice in there too: "Don't go out when it's cold. It depresses your immune system and makes you vulnerable to passing rhinoviruses." No doubt, there is some bullshit behind "masuk angin," but there may well be wisdom in it too.
And, hell, who am I to presume that I know how to sort out the pearls of wisdom from the bullshit? At least (as far as I know) the traditional healing methods haven't been conclusively proven as having no impact like Vitamin C, which is commonly sold in the West as a cold and flu cure-all...
Until then, bring on the awful tasting herbal medicines and burping masseurs...