Most cases of cervical rib are asymptomatic, discovered incidentally during routine chest x-ray interpretation. They occur in ~0.5% of population, but only 10% of patients with a cervical rib will be symptomatic.

Symptoms occur due to compression of either the brachial plexus (~95% of cases) causing pain and numbness of the upper limb, subclavian vessels causing upper limb swelling, pain, deep vein thrombosis (DVT) and ischemia or both neural and vascular elements.

Evaluation of thoracic outlet syndrome is done by Doppler ultrasound, contrast-enhanced CT, and MRI. Treatment is surgical in most cases.