There is no extra rib in females compared to males. Both men and women typically have 24 ribs (12 pairs). The idea that women have an extra rib is a myth stemming from a misinterpretation of the biblical creation story.
However, some individuals, both male and female, can be born with a cervical rib. This is an extra rib that forms above the normal first rib, at the base of the neck, just above the collarbone. Patient.info and NIDirect both describe it as occurring above the first rib. It's a congenital condition (present at birth), and while it's more common in females, it's not exclusive to them. Michigan Medicine mentions this higher prevalence in females. The prevalence in the general population ranges from 0.2% to 2%. NCBI A cervical rib doesn't necessarily cause problems, but if it compresses nerves or blood vessels, it can lead to thoracic outlet syndrome. Cleveland Clinic Johns Hopkins Medicine highlights the symptoms of thoracic outlet syndrome, such as pain, tingling, or weakness in the shoulder and arm.
In short, the common misconception about women having an extra rib is incorrect. The extra rib that some people, male and female, are born with is called a cervical rib and is located at the base of the neck.
