It turns out I have type 2 diabetes, which—from a patient’s point of view—boils down to a single data point: the amount of glucose in my bloodstream. Low is good; high is bad. Threatening my feet felt like a scare tactic, but the results of an undetected infection are very real for diabetics. We are often hit by a grim combination of weaker immune response and loss of feeling in the limbs, which can make a routine infection go very, very bad. And, like all 30 million Americans who have been diagnosed with diabetes, I face other potential complications, too: kidney, retinal, gum, and heart disease, never mind a high incidence of depression (unsurprisingly, it can be depressing to learn that you might lose a foot).