This is a curious condition where the shoulder begins to feel restricted and patients often get night pain in the early stages. It may be without a known cause, or there may be an underlying association such as diabetes, trauma or a neuromuscular problem. Indeed, it is so common in diabetics that they have a 10% lifetime risk of getting a frozen shoulder. The corollary is also true, in that if you are diagnosed with a frozen shoulder, there is a 75% chance you either have insulin resistance or diabetes.

It usually affects women between the ages of 30 and 60. It is mostly only in one arm, but up to 15% of patients experience it in both shoulders at the same time.