Patients ≥ 20 years of age being followed up at the outpatient clinics of the Internal Medicine Department in Medeniyet University Goztepe Training and Research Hospital and fulfilling the eligibility criteria will be included in the study. Approval of the local ethics committee and informed consent of the participants will be received for the study. The study is conducted in accordance with the Declaration of Helsinki. Demographic characteristics, concomitant diseases, smoking and alcohol drinking habits, concomitant medication usage, anthropometric and biochemistry data of the eligible patients will be recorded. Patient group will consist of patients with newly diagnosed Hashimoto thyroiditis and the control group will consist of healthy volunteers.