The COVID-19 pandemic introduced a wide range of symptoms beyond the respiratory system, including frequently reported musculoskeletal pain. This discomfort often involves the shoulder joint and surrounding muscle tissue. The relationship between the virus and shoulder pain is complex, manifesting differently across the timeline of infection, vaccination, and long-term recovery. Understanding the distinct causes—whether systemic, injection-related, or chronic—is important for accurate identification and management.
Shoulder Pain as an Acute COVID Symptom
Shoulder pain during an active SARS-CoV-2 infection is typically part of a broader, systemic response known as myalgia (muscle aches) or arthralgia (joint pain). This generalized aching is a common feature in the acute phase of the illness, reported by 15% to 45% of symptomatic patients. The pain is usually not caused by the virus directly infecting the joint, but rather by the body’s robust immune reaction.
The discomfort is driven by the release of pro-inflammatory signaling molecules, such as cytokines, which flood the body as the immune system fights the virus. This systemic inflammation affects muscle fibers and joint linings, leading to deep, widespread aches. For most people, this acute musculoskeletal pain is transient, typically resolving within 10 to 15 days as the body recovers from the initial infection.
Injection-Related Shoulder Pain
Shoulder pain following a COVID-19 vaccination falls into two categories based on severity and duration. The most common experience is temporary muscle soreness at the injection site. This is a normal, expected reaction indicating the immune system is responding to the vaccine. This mild soreness, swelling, and redness generally start soon after the shot and usually disappear completely within 24 to 48 hours.
A less common, but more serious, issue is Shoulder Injury Related to Vaccine Administration (SIRVA). SIRVA is a mechanical injury that occurs when the vaccine is injected too high or too deep into the shoulder. This improper technique bypasses the intended deltoid muscle and enters underlying joint structures, such as the subdeltoid or subacromial bursa or the rotator cuff tendons.
The introduction of vaccine material into these sensitive joint spaces triggers an intense, localized inflammatory cascade. This reaction can lead to conditions like bursitis or tendinopathy, resulting in severe and persistent pain. Symptoms of SIRVA include pain that is disproportionately severe compared to typical soreness, a limited range of motion, and discomfort that fails to resolve after a few days, often lasting for weeks or months. Specific diagnoses associated with SIRVA include adhesive capsulitis, commonly known as frozen shoulder.
Persistent Joint Discomfort in Long COVID
For some individuals, shoulder and other joint pain continues long after the initial COVID-19 infection has cleared, becoming a symptom of Post-Acute Sequelae of COVID-19 (PASC), or Long COVID. This chronic arthralgia is a frequently reported issue, lasting weeks or months beyond the acute phase. Shoulder pain in this context may be localized, or it can be migratory, moving between different joints over time.
One potential underlying mechanism for this chronic pain involves ongoing low-grade systemic inflammation. Even after the acute infection is over, the immune system may remain hyperactivated, continuing to produce pro-inflammatory molecules that affect musculoskeletal tissues. This sustained inflammatory environment can also trigger autoimmune responses, where the body mistakenly attacks its own healthy cells.
The persistent pain may be linked to the development of specific conditions, such as new-onset inflammatory arthritis or adhesive capsulitis, which causes shoulder stiffness and restricted movement. Researchers note that chronic pain in Long COVID patients often overlaps with symptoms of fibromyalgia, involving widespread tenderness and fatigue. Chronic muscle impairment following the infection may also contribute to prolonged soreness, especially after physical exertion.
When to Consult a Healthcare Provider
Seek medical advice if shoulder pain symptoms deviate significantly from a typical, transient ache. If injection site pain worsens after 24 hours or fails to resolve within two to three days, an evaluation is warranted to rule out a more serious injury. Pain severe enough to interfere with daily activities, such as reaching overhead or dressing, also requires consultation.
Other concerning signs include:
- Inability to move the arm.
- Pain accompanied by significant swelling.
- Discomfort that persists for longer than one to two weeks.
If shoulder pain is part of a cluster of other prolonged symptoms—such as debilitating fatigue, widespread aches, or neurological issues following an infection—discuss it with a healthcare provider to explore a possible diagnosis of Long COVID. While short-term management with rest, ice, or over-the-counter anti-inflammatory medications can help, a definitive diagnosis is necessary to determine the most effective long-term treatment plan.