**Core Concept**
Essential hypertension refers to high blood pressure with no identifiable cause, accounting for approximately 90-95% of all cases. It is characterized by a gradual increase in blood pressure over time, leading to cardiovascular complications.

**Why the Correct Answer is Right**
Essential hypertension is often associated with a family history, obesity, physical inactivity, and a diet high in sodium and saturated fats. The pathophysiology involves the renin-angiotensin-aldosterone system (RAAS) and the sympathetic nervous system, which regulate blood pressure through vasoconstriction and fluid retention. The kidneys play a crucial role in maintaining blood pressure homeostasis, and abnormalities in renal function can contribute to the development of essential hypertension.

**Why Each Wrong Option is Incorrect**
**Option A:** This option might be incorrect as essential hypertension does not typically present with a sudden onset.
**Option B:** This option might be incorrect as secondary hypertension, not essential hypertension, is often associated with kidney disease.
**Option C:** This option might be incorrect as pulmonary hypertension is a distinct condition characterized by high blood pressure in the pulmonary arteries.

**Clinical Pearl / High-Yield Fact**
It is essential to note that even mild elevations in blood pressure can increase the risk of cardiovascular disease. The American Heart Association recommends regular blood pressure monitoring and lifestyle modifications to prevent the progression of essential hypertension.

**Correct Answer: D**