Researchers conducted the first study on this matter back in 1990. The design was simple, and a bit rickety. They put four arthritis patients in a barometric chamber and subjected them to pressure changes akin to those that come with changes in weather. Three of the four patients experienced heightened pain when the pressure in the chamber dropped. Four participants makes for a pretty small sample size, but the study at least suggested some sort of link between joint pain and barometric pressure.

Before we get into more studies, let's define barometric pressure. Also known as atmospheric pressure, barometric pressure is basically a measure of how heavily the air weighs on us. This varies with weather — pressure drops right before a rainstorm, for example — and it also varies with altitude. On a mountaintop, barometric pressure is lower than it is at sea level; there's simply less air above you weighing down on you.

Recent studies on barometric pressure and joint pain have abandoned the pressure chamber for the real world. A 2007 study looked at reports of joint pain from 200 arthritis patients and found that spikes in self-reported pain correlated robustly with changes in barometric pressure and temperature. However, this correlation doesn't show up in every study — a 2017 study found no correlation between rainfall and insurance claims related to joint pain.

This doesn't necessarily mean the correlation is fictional, though — it could also mean that the pain increases storms bring on aren't severe enough to merit a visit to the doctor, or that doctors get booked so far in advance, it muddies the correlation.

One thing's for sure: Not everyone's bones can predict the future. Existing studies only support the idea that bones and joints weakened in some way — say, by age, osteoporosis, or injury — have an increased sensitivity to changes in barometric pressure.

From there, the data gets a little fuzzy. No one is exactly sure why these bones react to atmospheric changes, but there are some hypotheses floating around.

Some experts contend that changes in barometric pressure cause pain. Perhaps, they argue, drops in pressure allow "squishy" regions of the body, including the fluid that lubricates our joints, to expand. This, in turn, could trigger inflammation in arthritic or damaged joints — maybe by tripping nerves sensitive to pressure changes, called baro-receptors, which are found in load-bearing joints.

Other experts argue that changes in barometric pressure reveal pain that's already there. Our bodies naturally produce cortisol and adrenaline during the day, hormones that give us energy and suppress pain. At night, to help us sleep, production of both hormones drops — which means chronic pain becomes more palpable. This is all well-established. But intriguingly, production of cortisol and adrenaline also drops when barometric pressure drops — and this, some scientists argue, could account for all the bum knees that act up before a storm.

Ultimately, it's unclear how (and to what extent) joint pain and weather changes are linked, but it does seem like there's something there. "I feel it in my bones" is also a great idiom, and no one, not even science, can take that away from us.

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What about other old wives' tales? For those, check out "Don't Cross Your Eyes...They'll Get Stuck That Way! And 75 Other Health Myths Debunked" by Dr. Aaron E. Carroll and Dr. Rachel C. Vreeman. We handpick reading recommendations we think you may like. If you choose to make a purchase, Curiosity will get a share of the sale.