<p>Hypermobile Ehlers-Danlos syndrome (hEDS) is a heritable connective tissue disorder primarily known to cause abnormalities in the joints and skin. A variety of conditions are thought to commonly co-occur with hEDS. For the majority of these conditions, however, the prevalence among individuals with hEDS is unknown. In this study, the frequency of reporting of various medical diagnoses was explored in a cohort of 2,572 individuals with hEDS from the DICE Global Registry. The frequency of disease reporting in this cohort cannot be used to infer disease prevalence in the whole hEDS population. However, comparison with published prevalence rates for each condition among the general population gives insights into the extent of disease complexity in some hEDS populations likely to seek help for multisystemic disease. Similar to studies that have looked at these conditions individually or by body systems, most of the studied conditions were found at higher rates among the hEDS cohort than in the general population, with some exceptions. Notable examples include anxiety disorders, depressive disorders, irritable bowel syndrome, mast cell activation syndrome, and Sjogren’s syndrome. This information helps prevention of conditions from developing and improves screening for conditions that have already developed. It also provides participants with an increased understanding of their disorder and the symptoms they are experiencing.</p>