Study aim: Comparison of the effects of ginger and dexamethasone and ondansetron and promethazine in reducing postoperative nausea and vomiting in patients undergoing hysterectomy Design: The study will be double blind and clinical trial.100 patients will be randomly divide into 4 groups. The groups are parallel. The trial phase is 3. Settings and conduct: Patients who are candidates for hysterectomy at Sina Rezaei Ashtiani Hospital in Arak are divided into 4 groups using simple randomization with the envelope method. The study is double-blind, and blinding of the analyzer, outcome evaluator, and participant is performed. Participants/Inclusion and exclusion criteria: Inclusion Criteria: no history of cancer, no history of high blood pressure, 40 to 60 years, platelet count above 100000, no history of intestinal obstruction and hepatitis, no use of anti-nausea and anti-vomiting drugs or drugs that induce them, no long-term treatment with corticosteroid drugs, no history of allergy to ginger Exclusion Criteria: lack of patient's consent to participate in the study, willingness to cooperate, patients who experience cardiopulmonary arrest during surgery Intervention groups: Intervention Groups: Ginger Group:patients in the ginger group receive two 500 miligeram Vomegan Dineh ginger tablets, each containing 500 mg of ginger, one hour before the surgery. To standardize the appearance of the received medications, they also receive 4 millileter of distilled water in a serum. Ondansetron Group: patients in the ondansetron group receive 8 miligeram of ondansetron. Dexamethasone Group: patients receive 8 miligeram of dexamethasone intravenously before anesthesia induction. Promethazine Group:Patients receive 6.25 miligeram of promethazine intravenously before anesthesia induction. Main outcome variables: Nausea, vomiting, sedation