It’s pain and stiffness in your shoulder that happens slowly. It can worsen until your shoulder seems “frozen” in one position.
For example, it can happen if you can’t move your shoulder very well because of an injury or surgery, or if you have diabetes, which can worsen symptoms and make them last longer. Thyroid problems, Parkinson’s disease, heart disease,
Strong connective tissue called the shoulder capsule surrounds the ball end of your upper arm bone and holds it to the socket. Frozen shoulder causes this tissue to get thicker in parts (adhesions) and inflamed. This may limit the “synovial” fluid that normally lubricates the area and prevents rubbing. The result is pain and stiffness.
There are three stages.
Stage 1: Freezing
Over a period of 2 to 9 months, the shoulder capsule gets more and more inflamed. This ramps up pain and stiffness, and starts to limit your range of motion (how well you can use the joint). And these symptoms often get worse at night.
Stage 2: Frozen
As you might have guessed, this is when your shoulder is stiffest and hardest to move. It usually lasts somewhere between 4 months and a year. Pain often starts to improve in this stage. But your range of motion may be so limited that you find it hard to do basic things like eat, dress, and go to the bathroom
Stage 3: Thawing
Your shoulder pain should continue to ease during this stage, and now you start to regain some of your range of motion, too. It happens slowly, taking 6 months to 2 years. In some cases, you may get back all or almost all of your strength and mobility.