In this article:
- What are the symptoms of frozen shoulder?
- Causes and consequences of frozen shoulder
- Is thyroid disease a risk factor?
- Diagnosis and treatment
People with thyroid disease experience several symptoms that can affect every body system, including their joints and muscles. There is still speculation as to why thyroid disease affects the musculoskeletal system. Regardless, people with hypothyroidism, hyperthyroidism, and even thyroid nodules can experience muscle and joint problems. Here's a look specifically at frozen shoulder, a joint condition that appears to be more prevalent in people with thyroid disease.
What are the symptoms of frozen shoulder?
Frozen shoulder is as it sounds: it is a condition where the shoulder joint becomes stiff and painful. Also known as adhesive capsulitis, this condition tends to start with a gradual stiffness and worsens over time. Typically, it does resolve after one to three years.
A capsule of connective tissue keeps the shoulder bones, ligaments, and tendons together in the joint space. Frozen shoulder can occur when this connective tissue thickens with inflammation. Scar tissues may develop, which also limits the mobility of this joint.
Three stages are associated with this condition, and the length of each varies between people.
Pain and limited range of motion characterize the first phase of the frozen shoulder. The pain is most severe in the early stages of this condition and is often worse in the outer shoulder area. Sometimes, the pain will radiate down the arm.
The shoulder becomes stiffer during this phase and is extremely difficult to use. Some people find the shoulder becomes practically immobile, although the pain usually lessens in this phase.
The range of motion begins to improve, and pain continues to decrease.
Causes and consequences of frozen shoulder
There is much uncertainty when it comes to the causes of frozen shoulder. However, we know it is commonly seen in people over age 40 and is more likely to occur in women. People with endocrine disorders, such as diabetes and thyroid disease, are more likely to experience frozen shoulder. Additionally, those who must immobilize their arm for some time, such as after surgery or to support a broken bone, can experience this problem. Furthermore, people with cardiovascular disease, stroke, tuberculosis, and Parkinson's disease are also more likely to have frozen shoulder.
Frozen shoulder can have significant consequences for anyone with this condition. Losing mobility and experiencing pain in a joint can alter your lifestyle and affect your overall health and wellbeing. People with frozen shoulder have difficulty performing at work, maintaining the household, and brushing their teeth. Sleep can even be affected, which can cause fatigue and other secondary issues. Additionally, people with this condition often stray away from physical activity because it can worsen the pain, which can have detrimental consequences on weight management and muscle strength.
Is thyroid disease a risk factor?
Like other endocrine diseases, thyroid disease is considered a risk factor for frozen shoulder. People with too much or too little thyroid hormone can experience this condition. A 2020 study found that people with thyroid disorders (particularly hypothyroidism and benign thyroid nodules) were nearly three times more likely to have frozen shoulder than people without thyroid disease.
Several factors may unite these two conditions. Firstly, inflammation plays a vital role in both thyroid disease and frozen shoulder. Hashimoto's thyroiditis is an autoimmune disorder that results in hypothyroidism. Like most autoimmune diseases, inflammation is characteristic of Hashimoto's. Specifically, inflammation targets the thyroid gland in autoimmune thyroid disease. Yet, people with autoimmune diseases are likely to experience inflammatory processes in other tissues in their body, including the joints. We know that frozen shoulder is caused partly due to inflammation in the joint's connective tissue capsule.
Secondly, some research indicates that high TSH levels are associated with more severe frozen shoulder cases, including cases where both shoulder joints are affected. Typically, a frozen shoulder only occurs in one shoulder joint at a time.
Thirdly, people with both hypo- and hyperthyroidism can experience myopathy or muscle pain. Whether or not myopathy is related to frozen shoulder is up for debate. Still, people with thyroid disease are prone to experiencing muscle pain and stiffness.
Diagnosis and treatment
It can be challenging to diagnose frozen shoulder because the symptoms are often mistaken for other joint conditions, such as a torn rotator cuff. To diagnose frozen shoulder, your doctor assesses your pain level and evaluates your range of motion by guiding you through several shoulder movements. A frozen shoulder will make it difficult for both you and your doctor to move your shoulder.
Typically, reviewing your medical history and performing a physical assessment can help your doctor diagnose this condition. However, some people may need imaging studies, such as an MRI or X-rays, to rule out other joint problems. While thyroid disease (and endocrine disorders in general) are not diagnostic of frozen shoulder, your doctor may suggest a blood test to check your thyroid function.
Frozen shoulder often resolves with time and proper management. The primary concerns are managing pain and maintaining as much range of motion as possible. Thus, over-the-counter anti-inflammatories and pain relievers are often recommended (like Advil, Tylenol, and Motrin IB).
A doctor may prescribe a more potent pain reliever or even inject corticosteroids or sterile water to increase your mobility and decrease pain in more severe cases. Additionally, your doctor may perform various surgical procedures or perform shoulder manipulation while under general anesthesia. However, the need for surgery on a frozen shoulder is rare.
Also, physical therapy is extremely valuable for preserving your range-of-motion and helping to unfreeze the joint. Sometimes, people also use acupuncture and transcutaneous electrical nerve stimulation (TENS) to relieve the pain and stiffness.
Finally, if you have another health condition, like hypothyroidism, make sure you manage your condition with the proper thyroid medication and lifestyle modifications. Taking care of your thyroid is vital for your overall health and wellbeing.