What Is Frozen Shoulder?
Frozen shoulder is a condition that affects your shoulder joint. It usually involves pain and stiffness that develops gradually, gets worse and then finally goes away. This can take anywhere from a year to 3 years.
Your shoulder is made up of three bones that form a ball-and-socket joint. They are your upper arm (humerus), shoulder blade (scapula), and collarbone (clavicle). There’s also tissue surrounding your shoulder joint that holds everything together. This is called the shoulder capsule.
With frozen shoulder, the capsule becomes so thick and tight that it’s hard to move. Bands of scar tissue form and there’s less of a liquid called synovial fluid to keep the joint lubricated. These things limit motion even more.
Causes
It’s not clear why some people develop it, but some groups are more at risk.
Frozen shoulder happens more often in women than men, and you’re more likely to get it if you’re between the ages of 40 and 60. Your risk might also go up if you’re in the process of recovering from a medical condition like a stroke, or surgery like a mastectomy that keeps you from moving your arm.
Certain medical conditions can increase your risk too. You may also be more likely to get frozen shoulder if you have diabetes. About 10% to 20% of people with diabetes get frozen shoulder. Other medical problems like heart disease, thyroid disease, or Parkinson’s disease are linked to frozen shoulder, too.