Left Thoracic Outlet Syndrome: What to Know

Symptoms may include aching in the neck, shoulder or upper chest, tingling, numbness, heaviness, or weakness travelling into the left arm. Hand symptoms can become more noticeable when the arm is raised or used for a long time. If blood flow is affected, the hand may feel unusually cold, look pale or bluish, or swell. These features can overlap with other nerve, shoulder and circulation problems, so the symptom pattern and examination matter.

Arrange an assessment if symptoms persist, recur, or interfere with grip, sleep or daily tasks. A clinician may check neck and shoulder movement, sensation, strength, pulses and how symptoms change with arm position. Treatment often starts with activity adjustments and exercises that improve shoulder-blade control, chest flexibility and posture. Guided [Physiotherapy](/treatments/physiotherapy-and-rehabilitation/physiotherapy/) or [Postural Correction Therapy](/treatments/physiotherapy-and-rehabilitation/postural-correction-therapy/) may help, depending on the findings. Avoid repeatedly provoking symptoms while waiting.

Seek urgent medical care for sudden or worsening arm swelling, a cold or discoloured hand, marked weakness, severe chest or upper-back pain, or sudden breathlessness. Get prompt assessment for progressive numbness, loss of grip, or symptoms that begin after an injury. For background information, see [Thoracic Outlet Syndrome](/conditions/thoracic-outlet-syndrome/), [Arm Numbness and Tingling](/symptoms/arm-numbness-and-tingling/) and [Hand Numbness](/symptoms/hand-numbness/).

Could the pattern suggest nerve, vein or artery involvement? Which movements should I limit? Would imaging or nerve and circulation tests add useful information? What exercises are appropriate for my shoulder and neck?