The study was planned as a randomized controlled experimental study to determine the effect of inhalation use of ginger and peppermint on postoperative nausea and vomiting in patients undergoing thyroidectomy surgery. After the approval of the ethics committee and institutional permission, 81 patients who applied to the general surgery clinic for thyroidectomy between 1 December 2020 and 1 December 2021 and met the inclusion criteria will be included in the study. Within the scope of the planned study, the sample size in the light of the reported academic studies was determined as effect size d = 0.40 (effect size), α = 0.05 (margin of error), 1-β = 0.90 (Power) and by using the G-power package program with the specified criteria. It was decided to recruit 81 people (27 people per 3 group). Block randomization method will be used to determine the experimental and control groups. In order for the groups to be distributed homogeneously, the order produced by a computer program (https://www.randomizer.org/) will be used. Randomization will be done by a biostatistician outside the researcher. Patients who meet the inclusion criteria and agree to participate in the study will be assigned to the experimental and control groups according to the randomization list. Before the operation, the patient will be visited and information will be given about the purpose, content and intervention to be applied. After obtaining verbal and written permission from the patients who accepted to participate in the study, the "Informed Consent" will be filled in the "Patient Identification form. On the day of surgery, "surgical intervention information will be filled in by the researcher. In the postoperative period at the 2nd, 4th, 6th, 12th and 24th hours, the patient will use ginger and peppermint oil as inhalation. At the end of the 24th hour, the application will be terminated. In the control group, no application will be made during and after the surgical intervention, and routine treatment and care will be applied. After admission to the clinic of the patients in the experimental and control groups, the severity of pain, nausea and vomiting, the number of nausea-vomiting at the 2nd, 6th, 12th and 24th hours, the name, dose, frequency and time of the antiemetic drugs used were determined by the researcher. At the end of the 24th hour, Rhodes Nausea Vomiting Index score will be evaluated by the researcher.

The universe of the research; patients who are planned to undergo thyroid surgery between 1 December 2020 and 1 December 2021 in the general surgery clinic where the study will be conducted will comprise the patients who meet the inclusion criteria and agree to participate in the study. The research was planned as a randomized controlled experimental study. Block randomization method will be used to determine the experimental and control groups. In order for the groups to be distributed homogeneously, the order produced by a computer program (https://www.randomizer.org/) will be used. Randomization will be done by a biostatistician outside the researcher. Patients who meet the inclusion criteria and agree to participate in the study will be assigned to the experimental and control groups according to the randomization list. Research data will be collected in a hospital's general surgery ward between 1 December 2020 and 1 December 2021.

Independent variables of the research; age, gender, educational status, marital status, height, weight, habits and general health parameters were defined as independent variables. The dependent variables of the study are postoperative nausea-vomiting status (number and severity), pain severity (Visual Analog Scale-VAS), and Rhodes nausea-vomiting index score average.

Inclusion Criteria:

1. Those who are 18 years old or older,
2. According to the American Association of Anesthesiologists (ASA) classification; ASA score I and II,
3. Not known ginger and peppermint allergy,
4. Patients who are qualified to understand and answer questions in terms of cognitive capacity,
5. Patients without any psychiatric disorder,
6. Patients who agree to participate in the study will be included in the study.

Exclusion Criteria:

1. Under 18 years old,
2. Those with nutritional disorders,
3. Patients who require additional treatment to prevent nausea and vomiting, or patients using non-prescription anti-nausea and other complementary therapy,
4. Patients with peppermint and ginger allergy,
5. Those who have additional diseases (gastrointestinal system diseases, central nervous system tumors, vertigo etc.) that may affect the state of nausea and vomiting,
6. Not agreeing to participate in the research,
7. Those with respiratory diseases such as asthma, COPD, etc.