The root widely used to alleviate nausea, including nausea during pregnancy, is ginger. The underground part commonly called ginger root is the rhizome of Zingiber officinale, a plant related to turmeric and cardamom. It is eaten fresh, dried, powdered, candied, or prepared as tea.
Ginger has a long culinary and medicinal history across Asia and later became an important spice in trade between Asia, the Middle East, and Europe. Its pungent compounds, especially gingerols and related compounds formed during drying, contribute to its characteristic heat and flavor. Ginger preparations are used for several kinds of nausea, including motion-related nausea and morning sickness.
“Widely used” does not mean every product works equally well. Research on pregnancy-related nausea has found possible benefits, but some reviews judge the evidence limited or low quality, and dosage and medical history matter. Ginger may cause heartburn or stomach upset and can interact with some medicines, including anticoagulants, so persistent or severe pregnancy vomiting needs medical advice.