⚠️This fact has been debunked
The claim significantly overstates the prevalence of extra ribs. Medical research shows cervical ribs occur in 0.2-1% of the population (1 in 100 to 1 in 500 people), not 5% (1 in 20). While prevalence varies by population—ranging from 0.58% in Malaysian populations to 6.2% in Turkish populations—the 1 in 20 figure is not supported by medical literature.
One out of 20 people have an extra rib.
Do 1 in 20 People Really Have an Extra Rib?
You've probably heard that one out of every 20 people walks around with an extra rib. It sounds plausible—human anatomy varies, after all. But here's the twist: this "fact" is wildly off the mark.
The actual rate? About 1 in 100 people are born with an extra rib, called a cervical rib. Some studies put it even lower at 1 in 200 to 1 in 500. That's nowhere near the 5% claimed by the myth.
What Exactly Is a Cervical Rib?
A cervical rib is an extra bone that grows from the seventh cervical vertebra in your neck, just above your normal first rib. Most people have 12 pairs of ribs (24 total), but those with cervical ribs have at least one extra—sometimes two.
Here's the kicker: most people with cervical ribs don't even know they have one. These extra ribs are usually discovered by accident during X-rays or CT scans for unrelated issues. They're typically small, often incomplete, and cause zero problems.
When Extra Ribs Cause Trouble
About 1 in 10 people with cervical ribs develop a condition called thoracic outlet syndrome (TOS). This happens when the extra rib compresses nerves or blood vessels passing between your neck and armpit.
Symptoms can include:
- Numbness or tingling in the fingers
- Weakness in the hand or arm
- Pain in the neck or shoulder
- Coldness or color changes in the hand
But remember—90% of people with cervical ribs experience none of these issues. Their extra rib is just an anatomical quirk, like having attached earlobes or a hitchhiker's thumb.
Why the Myth Persists
So where did "1 in 20" come from? Likely from a game of medical telephone. Someone might have misremembered a statistic, or confused cervical ribs with other anatomical variations. Once a punchy number gets into circulation—especially one that sounds specific enough to be credible—it spreads.
The truth is more nuanced. Prevalence varies significantly by population. Studies have found rates ranging from 0.58% in Malaysian populations to as high as 6.2% in Turkish populations. Women are about twice as likely as men to have cervical ribs. But even at the highest estimates, we're still nowhere near that 1 in 20 figure.
The Takeaway
Human anatomy is wonderfully variable, and extra ribs are a real phenomenon—just not as common as this myth suggests. If you're curious whether you have one, you'd need medical imaging to find out. Chances are, though, you're in the 99% who have the standard rib count.
And if you do have an extra rib? Welcome to a pretty exclusive club—one that's much smaller than advertised.