Hammer syndrome? Wait a minute Jan – you’re already talking about Hypermobility Spectrum Disorders (HSD), multiple Ehlers-Danlos syndromes (EDS), Mast Cell Activation Syndrome (MCAS), and Postural Orthostatic Tachycardia Syndrome (POTS) among other things. You could say you’ve put the “syn” in syndromes, don’t you think? So what’s “Hammer Syndrome”?? Good news: it’s not a disease