Shoulder pain and loss of motion are symptoms of a condition called adhesive capsulitis. This is also known as “frozen shoulder.” Adhesive capsulitis is a common problem after shoulder tendinitis or bursitis. Another proposed cause is impingement from pinching of tissues in the shoulder.
Some people get this problem without knowing why. There wasn’t an accident, injury, or trauma. There is no arthritis. X-rays are normal. The problem simply comes on by itself. In these cases, it is called idiopathic.
If someone with a frozen shoulder has other problems, shoulder symptoms are often worse, and it usually takes longer to get better. The presence of other problems are called comorbidities. These are physical or social factors that affect a person’s health besides the main diagnosis. These could be other diseases such as diabetes mellitus or high blood pressure. Migraine headaches, low-back pain, cancer, depression, and tobacco or alcohol-use are all considered comorbidities.
In the case of idiopathic adhesive capsulitis, the most common comorbidities are low-back pain, diabetes mellitus, and high blood pressure. Social factors such as tobacco use and legal action also appear to slow healing. Without these comorbid factors, patients would have fewer symptoms and get well sooner.
Doctors can expect a longer treatment course and poorer results for some patients. This is especially true for frozen shoulder of an unknown cause when other physical or social problems exist.