Thoracic Outlet Syndrome: Symptoms and First Aid Awareness in Canada

Thoracic outlet syndrome (TOS) occurs when nerves and/or blood vessels are compressed in the space between the neck and shoulder, leading to symptoms that may affect the neck, shoulder, arm, and hand.

This area—known as the thoracic outlet—contains important nerves and blood vessels that travel from the neck into the arm. Compression in this space can interfere with normal circulation and nerve signals.

Understanding the Risk

Compression may develop gradually and is often associated with:

• Poor posture involving rounded shoulders
• Repetitive overhead arm movements
• Carrying heavy loads
• Previous shoulder or collarbone injuries

Some individuals are also born with structural differences that reduce the space in the thoracic outlet, increasing their risk.

Common Signs and Symptoms

Symptoms can vary depending on which structures are compressed, but may include:

• Shoulder or neck pain

• Tingling or numbness in the arm or hand

• Arm weakness or rapid fatigue

• Coldness or colour changes in the hand

• Symptoms that worsen with overhead activities

Because these symptoms overlap with other conditions, medical assessment is required for diagnosis.

First Aid Awareness: What to Do

Thoracic outlet syndrome cannot be diagnosed or treated with first aid, but awareness helps individuals recognize when symptoms should not be ignored.

Seek medical evaluation if:

• Arm numbness or weakness persists
• Circulation appears reduced (cold, pale, or bluish hand)
• Symptoms worsen with activity
• Pain interferes with daily tasks or sleep

If symptoms suddenly worsen, are severe, or include chest pain or breathing difficulty, activate emergency medical services immediately.

Why This Awareness Matters for Canadians

Repetitive work, prolonged desk posture, and physical labour are common contributors to shoulder and nerve-related symptoms in Canada. First aid training, primarily in standard first aid and advanced first aid courses, emphasizes:

• Recognizing warning signs of nerve and circulation issues
• Avoiding assumptions about “simple muscle strain”
• Seeking appropriate medical care early

Educational Disclaimer

This information is provided for general educational purposes only and does not replace professional medical advice. Thoracic outlet syndrome requires assessment by a qualified healthcare professional.