The present disclosure concerns antibodies specific for the Na v.7 polypeptides which are capable of antagonizing the biological activity of the Na v.7 polypeptide. The anti-Na v.7 antibodies can be used for alleviating the symptoms of pain and/or for treating or alleviating the symptoms of an hyperproliferative disease. The presence disclosure also concerns immunogens and methods for making antibodies, such as the anti-Na v.7 antibodies, comprising a single-domain antibody.