In most mammals, including humans, cervical ribs are not normally present as separate structures.

In humans, pathological cervical ribs are usually not of clinical concern, although they can cause a form of thoracic outlet syndrome.

[15] The presence of a cervical rib can cause a form of thoracic outlet syndrome due to compression of the lower trunk of the brachial plexus or subclavian artery.

Compression of the subclavian artery is often diagnosed by finding a positive Adson's sign on examination, where the radial pulse in the arm is lost during abduction and external rotation of the shoulder.

Recent studies have also found a high percent of cervical ribs in woolly mammoths.

Cervical ribs have been connected with leukaemia in human children, so it has given scientists new evidence to believe that the mammoth's extinction was attributed to the condition.