Why does rubbing salt in a wound hurt so much?As a metaphor, “rubbing salt in a wound” means to make an already-bad situation worse for someone, especially in an unnecessary or gratuitous way. One hears the phrase constantly, about everything from taxes to sports. Perhaps one reason it’s so common is that, even if most of us have never literally had a handful of Diamond Crystal rubbed into an open blister, we intuitively understand it to be painful, even unusually painful (after all, th...

Why don’t we all get heparin-induced thrombocytopenia?Way back in episode 59, we discussed why heparin, a commonly-used anticoagulant in the hospital, can cause mild hyperkalemia. The more widely-known side effect of heparin, though, is heparin-induced thrombocytopenia (HIT), of which there are two types: Type 1 (non-immune mediated) and Type 2 (immune-mediated). If a hospitalized patient suddenly has low platelets and is being anti-coagulated, HIT is always on the differential. However...