hypertension is defined as a sustained elevation of arterial blood pressure

Hypertension is defined as a sustained elevation of arterial blood pressure at a level of 140/90 or higher in persons between the ages of 1350 and 160/95 or higher in persons over 50 years of age. Hypertension is classified as primary (essential or idiopathic) or secondary. Primary hypertension, which constitutes approximately 90 % of the cases, has an unknown etiology. Secondary hypertension occurs as a result of other pathological conditions such a Cushings syndrome, increased intracranial pressure, renal disease, pheochromocytoma, and coarctation of the aorta. Hypertension is classified according to the degree of severity, ranging from Class I (mild hypertension with a diastolic pressure between 90104 mm Hg) to Class III (severe hypertension with a diastolic pressure above 115 mm Hg). Accelerated or malignant hypertension is characterized by a sudden and rapid rise of diastolic pressure above 120 mm Hg and concurrent Grade III-IV retinopathy. When the pressure elevation causes an immediate threat to the clients lifе, hypertensive crisis exists.
1) what is primary hypertension? 2) what is secondary hypertension? 3) when does hypertension crisis exist?
Найдите а тексте английские эквиваленты следующих российских слов и словосочетаний: кровяное давление, уровень, первичная гипертония, вторичная гипертония, синдром Кушинга, безызвестная этиология, гипертонический криз.