High blood pressure, or hypertension, most commonly occurs without any symptoms and has for this reason been referred to as the "silent killer." Uncomplicated hypertension can persist for years, even decades, without causing symptoms. However, when complications of the condition begin to develop due to damage to the vascular system, symptoms can occur. Symptoms of complicated hypertension (high blood pressure) can include

Other possible symptoms and signs are

nosebleeds,
blood in the urine,
fatigue,
chest pain, and
a pounding sensation in the neck, chest, or ears.

Severe high blood pressure is referred to as malignant hypertension, in which the diastolic ("bottom") blood pressure reading is over 140 mmHg. Malignant hypertension is a medical emergency and can cause stroke. Symptoms can include

nausea,
severe headache,
blurred vision, and
dizziness.

Some people with malignant hypertension may develop kidney failure. They may experience a decrease in urine output and swelling (edema), most pronounced in the lower legs.

Causes of high blood pressure

There are a number of factors that likely work together to cause high blood pressure.

A family history of high blood pressure can make you more likely to develop the condition, so genetics likely plays a role.
High salt intake (too much salt in the diet) or salt sensitivity occurs in some people, which can lead to hypertension, particularly in the elderly, African Americans, people who are obese, or people with chronic kidney (renal) disease.
Some people have blood vessels that are stiff and lack elasticity, due to vascular disease. When this affects the tiny arteries (arterioles), the arteriolar stiffness causes increased resistance to the flow of blood and high blood pressure. This is most common in people who are also obese, have a lack of physical activity or exercise, have high salt intake, and are older.