Shoulder pain is a common complaint that typically resolves with rest and conservative care, but sometimes it signals a serious underlying problem. Medical professionals use “red flags” to identify specific signs and symptoms that require immediate medical evaluation. These indicators help differentiate between a simple mechanical strain and a potentially dangerous condition, such as an infection, severe structural damage, or referred pain from an internal organ. Recognizing these signs is important because timely intervention can prevent long-term disability or address a life-threatening emergency.
Signs of Systemic Illness or Infection
Shoulder discomfort stemming from a systemic illness often presents differently from pain caused by a muscle or joint issue. A primary red flag is unrelenting pain that does not improve with rest or changes in position. This non-mechanical pattern, especially if the pain is severe and worsens at night, may suggest a deeper issue, such as a tumor or bone infection.
Pain accompanied by symptoms affecting the entire body, rather than just the shoulder, indicates a systemic problem. Unexplained fevers, chills, or night sweats can suggest an underlying infection, such as septic arthritis. Septic arthritis is a serious joint infection that causes inflammation, making the shoulder area feel warm, red, and swollen.
Unexplained loss of body weight over a short period is a serious concern when paired with chronic shoulder pain. This symptom, along with generalized fatigue, can be a sign of a malignancy or a chronic inflammatory condition like polymyalgia rheumatica. Patients with a history of cancer should be vigilant, as persistent shoulder pain may signal metastasis to the bone. Furthermore, a new, unexplained soft tissue mass or swelling warrants urgent investigation.
Indicators of Severe Structural Damage
Red flags related to structural damage focus on acute onset and immediate loss of function following an injury. Severe, sudden pain after a high-impact event, such as a fall or accident, could indicate a fracture or a complete joint dislocation. This acute, disabling pain should prompt immediate medical assessment to prevent further damage.
Any visible change in the contour or shape of the shoulder is a strong indicator of a severe structural issue. A noticeable bump, protrusion, or misalignment suggests a dislocation where the humerus has moved out of the socket. Similarly, a complete inability to lift or move the arm, known as true motor loss, may signify a large, acute rotator cuff tear or a severe joint injury.
Neurological symptoms extending beyond the shoulder joint signal potential nerve compression or damage. Sudden numbness, tingling, or weakness that radiates down the arm and into the hand suggests nerve pathology, such as severe nerve root compression or a brachial plexus injury. This rapid onset of sensory or motor deficit requires same-day emergency referral because nerve function can deteriorate quickly.
Referred Pain and Non-Orthopedic Causes
Some urgent red flags involve pain referred to the shoulder from a distant, non-orthopedic source, often within the chest or abdomen. Pain originating from the heart, such as during a heart attack or angina, can be felt in the left shoulder, neck, jaw, or arm. This cardiac pain is often described as a pressure or squeezing sensation in the chest, frequently accompanied by shortness of breath, dizziness, or sweating.
Referred cardiac pain is typically non-mechanical, meaning moving the shoulder joint itself does not affect it. The sudden onset of left shoulder pain combined with these systemic symptoms, especially difficulty breathing, necessitates calling emergency services immediately.
Shoulder tip pain can also be referred from irritation of the diaphragm, which is supplied by the phrenic nerve. This phenomenon, known as Kehr’s sign, is acute pain felt in the shoulder tip and is a classic symptom of internal abdominal bleeding or irritation. Conditions like a ruptured spleen, ruptured ectopic pregnancy, or other intra-abdominal hemorrhages can cause this referred pain. The pain may worsen when lying down or with elevation of the legs, prompting an urgent evaluation for an internal organ issue.