What are my odds of getting bent?

Short version: low — but I can't give you your number, and anyone who hands you one is selling a certainty they don't have. Here's the honest picture, and why it ends with me pointing you at people who know more than a webpage does.

Decompression sickness — "the bends," DCS — is what happens when you surface faster than your body can offload the inert gas it soaked up at depth, and that gas comes out of solution as bubbles where it shouldn't. (Ever wonder why it's called the bends? The name is older than scuba — it goes back to 19th-century caisson workers left stooped in pain; Wikipedia tells the story.) In recreational diving it's uncommon. The largest real-world study we have — DAN's analysis of nearly 128,000 dives — saw it in about half a percent of them. And even that is the rate in that dataset, not a law of nature stamped on your next dive.

That study is worth knowing about, because it's both reassuring and strange.

The reassuring part is the physics. The single biggest predictor of getting bent is exactly what you'd hope: how hard you pushed your decompression — how much excess gas was still dissolved in your tissues when you broke the surface. (That's the tissue-compartment model at work — the same Bühlmann math your dive computer runs.) Push closer to the line and the risk climbs steeply and predictably; dive conservatively and it stays tiny. That's the lever genuinely in your hands.

The strange part is everything else. The same study found women's odds ran several times higher than men's; that leaner divers were at higher risk, not heavier ones; that being warm and comfortable went with more DCS than being cold; that exercising beforehand doubled the risk; and that feeling tired before a dive was protective. Read those at face value and diving sounds deranged.

But most of them aren't about your body — they're about behavior and the limits of a questionnaire. "Feeling tired" almost certainly means the diver backed off and dove conservatively. "Exercise" couldn't be told apart from "exhausted myself hauling gear before splashing in." "Comfortable" tends to mean longer, deeper, more ambitious dives. The numbers are real; the obvious explanations are mostly wrong. A couple — the sex difference, the leanness one — might turn out to be real, but they rest on a single dataset with mechanisms still being chased in animal studies. And the model is blind to some of the things that matter most to you — whether you have a PFO, how hydrated you are, how your particular body makes bubbles — because the data never included them.

So here's the thing the statistics can't escape, and the reason this page ends the way it does. Every one of those findings is an average. Odds ratios, incidence rates, risk factors — they describe a population, a crowd, a center of gravity. They do not describe a person. The "average diver" in any study is a mathematical fiction, like the household with 2.3 children: useful for policy, owned by nobody. Honestly, if you're ever after a baby name guaranteed to make your kid famous overnight, call them Average — nothing in all of science gets referenced more. And yet, across everyone I've ever taught, I have not once met the average person these studies are about. Neither have you. Neither has the study.

That's not a knock on the science — it's good science, and you should respect what it says about the crowd. It's a knock on the idea that a chart or a calculator can hand you your risk. It can't. What comes closer is a human being who looks at your physiology, your training, your actual dives, and your history: a dive physician, your instructor, and the people at DAN, who exist for exactly this. Talk to them.

And hold on to the part that is yours. The data agrees on one lever above all others — don't push the line — and that's true per dive and across a whole trip. DAN's real-world injury files, the case reports rather than the rates, circle the same pattern over and over: aggressive, repetitive, multi-day diving. The liveaboard week of four and five dives a day with no break, and on day four a marbled rash spreads across someone's torso that a local ER waves off as an allergy. It's rarely one bad dive. It's the accumulation — yesterday's nitrogen you never fully shed riding into today, and the load building day over day.

You can't compute that load precisely either. But you can respect it: longer surface intervals, conservative profiles, nitrox, and — most underrated of all — rest days. My own rule, for whatever a sample size of one is worth: after three days of diving, if I've been doing more than three dives in a day, I take a day off. Not because a table told me to, but because the reef will still be there tomorrow, and I would rather lose a day than a week. Those same case files are full of divers who felt the first twinge and kept going anyway, talked into one more dive by a buddy. Don't be that diver. A deep joint ache, an odd patch of mottled skin, tingling that doesn't fit — that's the dive telling you it's finished. Call it, breathe oxygen, get evaluated.

You are not average. I'd stake my career on it, because I've spent it failing to find the person who is.

Sources: Marroni A, Kot J, Pieri M, Pelliccia R, Balestra C. "Identification of DCS risk factors in recreational diving: a multifactorial model based on the DAN DSL Database 2024." International Maritime Health, 2026; 77(1): 1–12. doi:10.5603/imh.108038 — and Nochetto M, Saraiva C, Chimiak JM. "Diving Injuries," in Tillmans F (ed.), DAN Annual Diving Report 2020 Edition. Durham (NC): Divers Alert Network; 2021.