The sensation of localized heat in the shoulder, often described as burning or warmth, is a common physical symptom. This feeling generally indicates an underlying inflammatory process within the joint or surrounding soft tissues. Inflammation is the body’s protective response to irritation, injury, or infection. The perception of heat is a direct result of increased blood flow to the affected area, which delivers immune cells and nutrients needed for tissue repair.
Heat from Soft Tissue Inflammation
Soft tissue inflammation is one of the most frequent causes of localized heat in the shoulder. This inflammation typically affects the tendons or the fluid-filled sacs that cushion the joint, a response often triggered by overuse or repetitive motion. The body reacts to micro-trauma by releasing chemical mediators, such as prostaglandins and bradykinin, which dilate local blood vessels.
This widening of blood vessels (vasodilation) increases the volume of warm blood rushing to the injured site, causing the skin to feel warm. Rotator cuff tendinitis, inflammation in the tendons that stabilize the shoulder, is a prime example of this irritation. Repetitive motions, especially overhead activities, can strain these tendons, leading to chronic inflammation and persistent warmth.
Bursitis, the inflammation of a bursa, also manifests with warmth and local tenderness. The subacromial bursa, located between the rotator cuff tendons and the acromion bone, can become irritated from friction or direct pressure. When this sac swells, the inflammatory process generates heat and pressure, which intensifies the burning sensation felt during movement or when lying on the affected side.
Heat from Joint Friction and Degeneration
A different source of localized heat arises from structural problems within the shoulder joint itself, primarily involving friction and the degeneration of cartilage. Osteoarthritis (OA) occurs when the smooth articular cartilage that covers the ends of the bones wears down over time. This loss of cushioning causes the bones to rub together during movement, generating mechanical friction.
This friction causes pain, a grinding sensation, and sparks a prolonged inflammatory response confined largely to the joint capsule. The constant low-grade inflammation produces a sustained warmth felt deep inside the shoulder.
Shoulder Impingement Syndrome is another mechanical issue where soft tissues are repeatedly compressed, which can lead to friction-related inflammation. In this condition, the tendons or bursa become pinched in the narrow space beneath the acromion, the bony top of the shoulder blade. The mechanical irritation from this pinching causes a localized inflammatory reaction, which includes the sensation of heat and pain, particularly when the arm is lifted overhead.
When the Sensation is Nerve-Related or Systemic
The perception of a burning or hot sensation is not always caused by actual heat from inflammation; sometimes it is a result of nerve irritation, a phenomenon known as neuropathic pain. Nerve entrapment, often stemming from the cervical spine (neck), can cause a burning sensation that radiates down the arm and into the shoulder. This happens because pressure on the nerve interferes with its signaling, and the brain misinterprets the abnormal signal as a burning feeling, even if the skin temperature is normal.
A more urgent cause of heat is a systemic issue, such as an infection. Cellulitis is a bacterial infection of the skin and underlying tissues that causes the area to be intensely warm, red, and swollen. A more serious condition is septic arthritis, which is a bacterial infection within the joint space.
Both cellulitis and septic arthritis cause excessive warmth, often accompanied by systemic symptoms like fever, chills, and severe pain. This heightened immune response requires immediate medical intervention to prevent joint destruction or the spread of infection.
Immediate Self-Care and When to Consult a Doctor
For the most common causes of shoulder heat related to simple inflammation or overuse, immediate self-care can help manage symptoms. The R.I.C.E. principle is a practical starting point, beginning with resting the shoulder and avoiding activities that aggravate the pain. Applying a cold compress or ice pack to the affected area for 15 to 20 minutes several times a day helps reduce both inflammation and the sensation of heat.
Over-the-counter nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen or naproxen, reduce the chemical inflammation that contributes to warmth and pain. These medications work by blocking the production of inflammatory chemicals at the injury site. If symptoms are mild and improving with self-care, a doctor’s visit may not be immediately necessary.
When to Seek Medical Attention
Certain symptoms warrant a prompt consultation with a healthcare professional. Seek medical attention if you experience any of the following:
- The heat is accompanied by a fever or chills.
- The pain is so intense that you cannot move your arm.
- You notice a spreading area of redness and swelling.
- Warmth and pain persist beyond five to seven days despite consistent self-care.