Malignant HTN? Your BP will almost always be over 120 diastolic, you may go blind from eye hemorrhages, you may die from kidney or heart failure. Your doctor can look into your eyes and see hemorrhage and exudates and a swollen disc. You your self may not know at all as it can be silent. This is the reason it is called the silent killer. Most are dead in 1 year with untreated malignant HTN.
It's rare. Malignant hypertension is an older term for a situation in which very high BP (usually chronic) causes brain swelling. The swelling can be detected by examination of the optic fundus (back of the eyeball) where protrusion of the optic nerve head is seen: this is termed papilledema. This condition may be associated with blurred vision.