Does missed period or irregular period causes nausea?

Perhaps a different: Question - is the nausea caused by something else that could also affect menses? I am not aware of irregular menses causing nausea. However, being stressed, perhaps sick (with nausea) could delay menses. Of course, some women early in pregnancy have "morning sickness", with nausea and vomiting. Please see your doctor for a complete history and physical. A pregnancy test may also be helpful.

Depends: Irregular periods do not cause nausea unless you are pregnant and/or there are other underlying conditions that cause the irregular periods as well as the nausea such as emotional or physical stress, adrenal disease, excessive production of a hormone call prolactin etc.. If you have irregular periods +/- nausea you should see your OB gyn for an evaluation.