I have hypermobile joints, asthma, ibs and anxiety - peer reviewed medical research shows that these conditions are linked, but is it widely known?

Hypermobility: Joint hypermobility, possibly Ehlers-Danlos syndrome type III, and orthostatic hypotension are related. Asthma, irritable bowel syndrome and anxiety are also about as common as hypermobility. You cannot "fix" hypermobility but you can make your body more fit with small doses of aerobic exercise. Muscle strengthening is also helpful in stabilizing loose joints and improving function.