Flexible joints that cause pain, dislocations, or fatigue often lead to one of two labels: hypermobile Ehlers-Danlos syndrome (hEDS) and hypermobility spectrum disorder (HSD). The two overlap so much that the line between them confuses patients and clinicians alike.

At least half a million people in the U.S. have hEDS or HSD. Most are undiagnosed. Here is what that looks like in practice.

The Ehlers-Danlos syndromes (EDS) are a group of inherited conditions that affect connective tissue.