1. How much blood the heart pumps with each beat (stroke volume). Can be affected by certain hormones, stress, drugs, and diseases, as well as increases or decreases in the amount of blood in the body, called blood volume

2. How fast the heart beats (heart rate)  When heart rate increases, blood pressure rises.  When heart rate decreases, blood pressure drops.  Affected by nervous system, hormones, body temperature, medications, and diseases.

3. How difficult it is for blood to travel around the body (vascular resistance).  Width of the arteries.  Blood pressure normally remains pretty stable. The body adjusts the resistance of the arteries, either widening or narrowing them, to prevent the blood pressure from swinging wildly.  Most of the regulation of blood pressure occurs in the arterioles.

Atherosclerosis

Sphygmomanometer / Stethoscope

Systolic (Top Number) This is the amount of pressure your heart generates when pumping blood out through your arteries. Diastolic (Bottom Number) This is the amount of pressure in your arteries when your heart is at rest between beats.

Blood pressure is controlled by the brain.  If the blood pressure increases, the brain sends nerve impulses to the heart and to the arterioles, causing the heart rate to slow and the arterioles to widen (vasodilatation). As a result the blood pressure decreases.  If the blood pressure becomes too low, the brain sends impulses that cause the heart rate to increase and the arterioles to narrow (vasoconstriction), increasing the blood pressure.  If this regulatory mechanism cannot bring the blood pressure to normal levels, hypertension or hypotension can result.

 A “silent killer”, there are usually no symptoms.  If not addressed in time can cause irreversible damage to the organs of the body (stroke, heart attack, kidney failure...)  In 90% of the cases of hypertension, the cause is unknown.

Diuretics - Rid the body of excess fluids Beta-blockers - Reduce the heart rate and the work of the heart Vasodilators - Cause the muscle in the wall of the blood vessels to relax, allowing the vessel to dilate (widen)

Risk Factors You Can Control  Smoking  Physical Inactivity  Obesity  Diet (Salt Intake)  Diabetes  Stress Risk Factors You Can’t Control  Age  Ethnicity (South Asians, First Nations/Aboriginal Peoples or Inuit and Blacks are at increased risk)  Family history

Stress Your body reacts to stressful situations by releasing adrenaline – that causes your breathing and heart rate to speed up and your blood pressure to rise (fight or flight response) Once the stressor disappears, your blood pressure should return to normal. However, spikes in blood pressure —if they occur often enough —can damage your blood vessels, heart and kidneys.