The article compares a routine full‑body MRI to activities that carry a similar risk, roughly equivalent to a year of smoking. It cautions against screening asymptomatic people, noting that tests work best on those already more likely to be sick. The author reviews Scott Alexander’s analysis, focusing on quality‑adjusted life years (QALYs).

Of 1,000 people scanned, 680 finish with only a brief doctor visit, costing 0.0003 QALYs. 296 incur additional waiting and testing, costing 0.02 QALYs, while 10 face unnecessary biopsies, costing 0.06 QALYs. Six detect a problem but gain no benefit; 4 benefit early with a net gain of 3.99 QALYs after side‑effect costs; another 4 gain the same benefit after extra testing, still net 3.99 QALYs. Summing yields a net benefit of 0.025 QALYs per person.

The author translates this to micromorts, finding 1 QALY ≈ 37,000 micromorts, so 0.025 QALYs ≈ 926 micromorts. This matches the risk of riding 10,000 km on a motorcycle or doing two base jumps—activities that also carry about 1,000 micromorts. The piece ends by noting that whether one is willing to avoid such risks depends more on personal preference than on objective danger.