Observational Study to Evaluate the Safety and Efficacy for Levacalm Tab. Versus Valsartan/Amlodipine Combination Therapy in Essential Hypertension Patients

Inclusion Criteria: * patients aged over 19 with essential hypertension * Those who meet the inclusion criteria, fall under any of the following 3 cases and determined by the investigator to be prescribed Levacalm or Valsartan/Amlodipine combination: 1. those who can't maintain the blood pressure with the antihypertensive drug before. 2. those who diagnosed to a hypertension stage 2.(DBP is higher than 160mmHg or SBP is higher than 100mmHg) 3. those who fall under the following :cardiovascular disease, Cerebrovascular disease, chronic Renal disease, diabetes mellitus, peripheral vascular disease * Those who were informed of the purpose, method, and effect etc. of this study and signed the informed consent form. Exclusion Criteria: 1. Those who are included in the contraindication of study drug following the information for use of the product 2. Those who is/will be participated in other drug clinical trial 3. Those who adminitrated other antihypertensive drugs beside the levacalm or Valsartan/amlodipine combination drug. 4. Those who judged by the invesigator as ineligible for this clinical study