The present invention relates to antibodies that bind to the IL-4 receptor, fragments, muteins, and derivatives of such antibodies, nucleic acids encoding such antibodies, fragments, muteins and derivatives, and methods of making and using such antibodies, fragments, muteins, derivatives and nucleic acids. Methods for treating medical conditions induced by interleukin-4 involve administering an IL-4 receptor binding antibody, or an IL-4 receptor binding fragment, mutein, or derivative of an IL-4 receptor binding antibody, to a patient afflicted with such a condition. Particular antibodies provided herein include human monoclonal antibodies. Certain of the antibodies inhibit both IL-4-induced and IL-13-induced biological activities.