Signs of blood pressure problems are not always abundant or clear. According to the National Heart Lung and Blood Institute, a division of the National Institutes of Health, elevated blood pressure or hypertension typically has no signs or symptoms, and a person can have high blood pressure for years without knowing it. Likewise, hypotension, or lower than normal blood pressure, has few signs or symptoms. Nevertheless, if left unchecked, blood pressure problems can cause significant adverse health effects.
Dizziness & Fainting
Dizziness and feinting may be signs of hypotension or low blood pressure. According to the MayoClinic.com website, although low blood pressure may seem to be advantageous, it can cause symptoms of dizziness and fainting or it can indicate the presence of a serious underlying heart, endocrinal or neurological condition. Severely low blood pressure can starve the brain and vital organs of blood, oxygen and nutrients, which can lead to a life-threatening situation known as shock. The MayoClinic.com notes that orthostatic hypotension, which is also called postural hypotension, is a type of low blood pressure that occurs when a person stands up after sitting or lying down for prolonged periods. Orthostatic hypotension causes feelings of dizziness and can lead to fainting. Possible causes of orthostatic hypotension include heart problems, diabetes, adrenal deficiency and certain nervous system disorders, such as Parkinson's disease.
Abnormal Blood Pressure Readings
Abnormal blood pressure readings are the most definitive signs of blood pressure problems. The National Heart Lung and Blood Institute states that it's important for a person to know his blood pressure numbers, even if he's feeling fine. If a person's blood pressure numbers are normal, he can work with his health care team to maintain a healthy blood pressure. If a person's numbers are too low or too high, he will need to follow a treatment plan to normalize his values and avoid organ damage or treat any underlying pathology. Blood pressure numbers include systolic and diastolic pressures. Systolic pressures, the top number in a blood pressure reading, indicate the pressure on the arterial walls when the heart beats. Diastolic blood pressure, the bottom number in a blood pressure reading, represents the pressure when the heart is at rest between beats. A typical healthy blood pressure is 120/80 mm Hg.
Dehydration & Thirst
Dehydration and unusual thirst are signs of low blood pressure. According to the American Heart Association, dehydration--a potentially life-threatening condition in which the body loses more water than it takes in--can cause blood pressure to drop, although dehydration is not always indicative of low blood pressure. Common causes of dehydration include a fever, vomiting, severe diarrhea, diuretics and vigorous exercise. The AHA notes that even mild dehydration, such as a loss of 1 to 2 percent of body weight, can cause weakness, dizziness and fatigue. The MayoClinic.com states that hypovolemic shock, the most severe complication of dehydration, occurs when the body's low blood volume triggers a sudden decrease in in blood pressure and a significant reduction in the volume of oxygen reaching the cells, tissues and organs. Left unchecked, hypovolemic shock can cause death within minutes.
