You must have felt it—or at least heard people around you complain about a sudden, persistent stiffness in the shoulder that makes even simple movements painfully difficult. For many, this seemingly innocuous discomfort turns out to be frozen shoulder, clinically known as adhesive capsulitis—a condition characterised by enduring shoulder pain and significantly restricted mobility which affects 3–5 per cent of the general population and as much as 20 per cent of people with diabetes.

This becomes a matter of urgent concern for India, which is often termed the diabetes capital of the world. According to the International Diabetes Federation (2024), India’s total adult population stands at over 94.7 crore, with a 10.5% prevalence of diabetes, meaning nearly 8.98 crore adults live with diabetes today. With diabetes being one of the strongest risk factors for frozen shoulder, understanding the condition and its treatment options becomes crucial for effective management and prevention.

What is frozen shoulder? 

Frozen shoulder is a painful condition in which the movement of the shoulder joint becomes severely limited. Clinically termed adhesive capsulitis, it occurs when the strong connective tissue surrounding the shoulder joint – known as the shoulder joint capsule, becomes tight, thickened, and inflamed. This capsule encases the ligaments that connect the upper arm bone (the humeral head) to the shoulder socket (glenoid), forming the ball-and-socket structure that allows fluid movement in multiple directions.

As inflammation sets in, the joint capsule begins to stiffen. Over time, adhesions, thick bands of scar tissue, form within the capsule, reducing the amount of synovial fluid that lubricates the joint. This progressive tightening makes every movement of the shoulder painful and limited. The condition is described as “frozen” because pain discourages the use of the affected arm. The less the shoulder is used, the stiffer and tighter the capsule becomes, effectively locking the joint and severely restricting its range of motion.

Frozen shoulder often develops gradually, and without timely intervention, it can severely impact daily activities such as dressing, reaching overhead, or even sleeping comfortably. While the exact cause remains unknown, the condition is commonly associated with prolonged shoulder immobility following an injury or surgery, systemic illnesses such as diabetes, thyroid disorders, Parkinson’s disease, and cardiovascular issues.

What are the symptoms and causes? 

Frozen shoulder typically progresses through three clinical stages, each lasting several months. The first is the “freezing” stage, where pain starts gradually and intensifies over time. Movement becomes increasingly difficult, and pain often worsens at night, disturbing sleep. This stage usually lasts six weeks to nine months. The second phase is the “frozen” stage, during which pain may begin to decrease, but stiffness remains severe. Daily tasks become more challenging, and functional limitations are prominent. This phase may last two to six months. The final phase is the “thawing” or recovery stage, where movement slowly begins to improve, and pain diminishes. Full recovery can take anywhere from six months to two years.

Although the exact reason frozen shoulder develops remains unclear, researchers believe the process begins with inflammation within the joint capsule. As inflammation persists, the capsule thickens and tightens. Scar tissue forms and synovial fluid reduces, compromising lubrication and restricting shoulder movement. In many cases, this inflammation-fibrosis cycle is associated with systemic health conditions, metabolic factors, or immobilisation following trauma.

Several factors increase the likelihood of developing frozen shoulder. Age is a major determinant, with the condition most common between 40 and 60 years. Women are more prone to the condition than men. A history of shoulder injury or surgery that requires immobilisation, such as for a rotator cuff tear or fractures of the collarbone or upper arm, significantly increases risk. Diabetes is one of the strongest contributors: 10%–20% of people with diabetes are known to develop frozen shoulder. Other conditions such as stroke, hyperthyroidism, hypothyroidism, Parkinson’s disease, and heart disease have also been associated with the condition. Stroke, in particular, limits shoulder movement, triggering stiffness, while the mechanisms linking other systemic diseases to frozen shoulder remain less clear.

How common is frozen shoulder in India? 

The burden of frozen shoulder in India has been observed across various clinical and population-based studies, particularly among individuals with diabetes.

Dr Raju Vaishya, Senior Consultant, Orthopaedics and Joint Replacement Surgery at Indraprastha Apollo Hospitals, Delhi, explained that frozen shoulder, medically known as adhesive capsulitis, is fairly common in India and affects around 2 to 5 per cent of the general population.

He noted that the prevalence rises sharply among people with diabetes. “In diabetic patients, frozen shoulder becomes five to ten times more common, affecting nearly 10 to 20 per cent of them,” he said. With the steady increase in diabetes across the country, Dr Vaishya added that the number of frozen shoulder cases has also grown.

He explained that sedentary lifestyles, delayed medical attention, self-treatment, and post COVID inflammatory changes may be contributing to this rise. “People often wait for months before seeing a doctor. Increased awareness and more frequent consultations with orthopaedic surgeons and rheumatologists have also contributed to higher detection rates,” he noted.

Dr Vaishya’s observations have been reaffirmed by multiple studies. A 2018 study conducted at the Diabetic Care and Research Center, S.P. Medical College and Associated Group of P.B.M. Hospitals, Bikaner, concluded that the prevalence of frozen shoulder and associated complications was significantly high in the diabetic population of northwest India and that early detection and proper care could prevent much of the disability associated with the condition.

A 2024 observational study reported that “frozen shoulder was observed in 11% of diabetic cases, highlighting the need for routine screening in this population.” (sic.) The study emphasised the value of systematic screening to enable early diagnosis and timely management in individuals with diabetes, a population already vulnerable to musculoskeletal complications.

Another 2024 cross-sectional study observed that glycosylation processes in diabetic individuals may lead to collagen stiffening, contributing to the development of adhesive capsulitis. The study concluded that “participants with uncontrolled diabetes have high risk towards developing frozen shoulder. Duration of pain in DM was directly proportional to the high risk of frozen shoulder and females were more affected than males.”

Beyond diabetes, Dr Vaishya identified several other risk factors. He said that prolonged immobilisation after fractures, shoulder injuries or surgeries can significantly raise the likelihood of developing the condition. “Even hospitalisation after events such as a heart attack can lead to prolonged immobility and increase the risk,” he explained.

He added that thyroid disorders, cardiac diseases, autoimmune conditions such as rheumatoid arthritis, post COVID inflammation, age related hormonal changes and connective tissue disorders are also linked to frozen shoulder.

On why women are slightly more affected, Dr Vaishya pointed to a mix of hormonal and health related factors. “Frozen shoulder typically affects people between the ages of 40 and 60. Women, especially during the perimenopausal and menopausal phases, experience hormonal changes that influence connective tissue elasticity and inflammation,” he said. He also noted that women have a higher prevalence of autoimmune and thyroid disorders, which further increases their susceptibility to the condition.

What is the best treatment for frozen shoulder?  

Dr Vaishya explained that frozen shoulder progresses through three distinct stages, each requiring a different approach to treatment. In the first phase, often called the freezing stage, pain gradually increases and stiffness begins to set in. “At this early stage, pain control is crucial. We usually manage it with non-steroidal anti-inflammatory drugs, short-term oral steroids and, in some cases, injections into the joint. Gentle range of motion exercises must begin at this point,” he said.

If the condition advances, it enters the second phase, known as the frozen stage. Movement becomes severely restricted, and stretching the shoulder becomes painful. “This is when the joint feels completely locked. Heat therapy, along with consistent exercises, is essential to regain mobility,” Dr Vaishya noted.

The final phase is the thawing or recovery stage, during which stiffness gradually eases. According to him, this is a self-limiting condition that slowly improves over time. “During recovery, patients should continue range-of-motion and strengthening exercises. In some cases, we use hydrodilatation, which involves injecting fluid into the joint to stretch the capsule and relieve stiffness,” he explained.

He added that arthroscopic capsular release is reserved for only the most resistant cases. “Surgery is required in barely five per cent of patients,” he said.

Most individuals recover within six to 18 months. “If left untreated, frozen shoulder can trouble patients for up to two years. Early diagnosis and timely treatment dramatically shorten the recovery period,” he emphasised.

Dr Vaishya also highlighted the importance of awareness and early medical care. Many patients, especially in smaller towns, delay seeking help. “People often self-medicate and come to us after three to six months. Recognising symptoms like persistent shoulder pain, night discomfort, difficulty wearing clothes or combing hair is crucial,” he said.

He advised maintaining regular shoulder movement after injuries or periods of inactivity and controlling underlying conditions such as diabetes and thyroid disorders. “Prolonged immobilisation increases the risk. If pain lasts beyond two to three weeks, it is better to consult a doctor rather than rely on painkillers,” he added.

Also read: Why women’s chest pain is often dismissed: Understanding atypical angina