The purpose of this study is to see if Candesartan, once daily (QD), added with Hydrochlorothiazide may be helpful in treating people with newly diagnosed severe essential hypertension.

Medical data show a link between blood pressure and the risk of heart disease (cardiovascular disease) such as stroke and heart attack. Clinical trials have shown that lowering blood pressure in patients with high blood pressure (hypertension) reduces the number of cardiovascular events.

Many people still have untreated hypertension. There are many reasons why target blood pressure is not reached. One is that most patients need more than one antihypertensive drug in order to lower high blood pressure. Other reasons include poor patient compliance with taking their drugs.

Combining drugs that lower high blood pressure and have similar ways of working in the body may help high blood pressure and lower the risk for medication-related side effects. One of several drug combinations recommended for the treatment of high blood pressure is an angiotensin receptor blocker and a thiazide diuretic. Guidelines also note that combination tablets may improve patient compliance with taking their drugs.

Candesartan is an angiotensin type-1 receptor blocker. Hydrochlorothiazide is a diuretic with blood pressure-lowering effect. This study will combine both of these drugs in one pill and see how it works in people taking part in this study.

Inclusion Criteria:

• Confirmed diagnosis of essential hypertension.
• Has Systolic Blood Pressure between 150 mmHg and 200 mmHg AND Diastolic Blood Pressure between 110 mmHg and 120 mmHg.
• Has not received any antihypertensive treatment so far.
• Has a negative pregnancy test at baseline in females of childbearing potential. Male and female participants with reproductive potential must use an approved contraceptive method during study treatment evaluation

Exclusion Criteria:

• Has a known or suspected secondary hypertension or primary hyperaldosteronism.
• Has impaired renal function.
• Has severe hepatic impairment.
• Has bilateral renal artery stenosis, solitary kidney or post-renal transplant status.
• Has a history of myocardial infarction, coronary artery bypass graft, percutaneous coronary intervention or cerebral accident (stroke or transient ischaemic attack) within the last 6 months.
• Has a diagnosis or suspicion of the following conditions: hypertrophic obstructive cardiomyopathy, angina pectoris, chronic heart failure, peripheral arterial occlusive disease, hypertensive retinopathy.
• Has hemodynamically relevant stenosis of the aortic or mitral valve.
• Has clinically relevant and refractory hypokalaemia or hyperkalaemia.
• Has uncorrected volume or sodium depletion.
• Has gout or relevant hyperuricaemia.
• Has a known intolerance/hypersensitivity to Candesartan cilexetil or Hydrochlorothiazide.
• Has a known galactose intolerance, lactase deficiency or glucose-galactose malabsorption.
• Is taking psychotropic medication or is addicted to alcohol or drugs.
• Has participated in another trial of an investigational drug or a medical device within the last 30 days or is currently participating in another trial of an investigational drug or a medical device.