High Blood Pressure Symptoms High blood pressure usually causes no symptoms. Even if high blood pressure does cause symptoms, the symptoms are usually mild and nonspecific (vague, or suggesting many different disorders). Thus, high blood pressure often is labeled the silent killer. People who have high blood pressure typically don t know it until their blood pressure is measured. Sometimes people with high blood pressure have symptoms including headache, dizziness, blurred vision and nausea. People often do not seek medical care until they have symptoms arising from the organ damage caused by chronic (ongoing, long-term) high blood pressure. The following types of organ damage are commonly seen in chronic high blood pressure: heart attack, heart failure, stroke or mini stroke (transient ischemic attack, TIA), kidney failure, eye damage with loss of vision, peripheral arterial disease. About 1% of people with high blood pressure do not seek medical care until the high blood pressure is very severe, also called malignant hypertension. In malignant hypertension, the diastolic blood pressure (the lower number) often exceeds 140 mm Hg. Malignant hypertension may be associated with headache, light-headedness, or nausea. This degree of high blood pressure requires emergency hospitalization and lowering of blood pressure to prevent brain hemorrhage or stroke. It is of utmost importance to realize that high blood pressure can be unrecognized for years, causing no symptoms but causing progressive damage to the heart, other organs, and blood vessels.