This is a prospective, multicenter, observational study to evaluate the effectiveness of Olmetec® or Olmetec Plus® on nocturnal blood pressure control in Korean patients with stage 1 hypertension. Patients receiving Olmetec-based therapy in routine clinical practice will be followed to assess changes in ambulatory blood pressure, including nocturnal blood pressure and blood pressure variability.

This is a prospective, multicenter, observational study designed to evaluate the effectiveness of Olmetec® (olmesartan medoxomil) or Olmetec Plus® (olmesartan medoxomil/hydrochlorothiazide) on nocturnal blood pressure control in Korean patients with stage 1 hypertension.

In routine clinical practice, patients diagnosed with stage 1 hypertension and newly prescribed Olmetec® or Olmetec Plus® according to the approved label and the physician's clinical judgment will be enrolled and followed prospectively. No additional intervention beyond standard medical care will be applied.

Ambulatory blood pressure monitoring (ABPM) will be used to assess 24-hour blood pressure profiles, including nocturnal blood pressure, daytime blood pressure, and blood pressure variability. Measurements will be performed at baseline and after treatment to evaluate changes over time.

The primary objective of this study is to assess the change in mean systolic blood pressure from baseline to 12 weeks (up to 20 weeks). Secondary objectives include evaluation of diastolic blood pressure, nocturnal blood pressure, blood pressure variability, responder rate, and changes in dipping patterns. Safety will be assessed by monitoring adverse events during the study period.

This study aims to generate real-world evidence on the effectiveness and safety of Olmetec-based therapy in controlling nocturnal blood pressure and improving blood pressure variability in patients with stage 1 hypertension.

Inclusion Criteria:

• Adults aged ≥19 years
• Patients diagnosed with stage 1 hypertension according to clinical guidelines
• Patients who are newly prescribed Olmetec® or Olmetec Plus® in routine -clinical practice
• Patients who are able to undergo ambulatory blood pressure monitoring (ABPM)
• Patients who voluntarily agree to participate and provide written informed consent

Exclusion Criteria:

• Patients with secondary hypertension
• Patients with severe hypertension requiring immediate pharmacological i-ntervention
• Patients with known hypersensitivity to olmesartan medoxomil, hydrochlorothiazide, or any component of the study drugs
• Patients who are pregnant, planning to become pregnant, or breastfeeding
• Patients with severe renal impairment or severe hepatic impairment
• Patients who are unable to comply with study procedures, including ABPM
• Patients who are deemed inappropriate for participation by the investigator

Patients with stage 1 hypertension in Korea who are newly prescribed Olmetec® or Olmetec Plus® according to routine clinical practice. Eligible patients are adults who meet the inclusion and exclusion criteria and are able to undergo ambulatory blood pressure monitoring (ABPM).