Blood pressure is a measurement that indicates the force of blood against the walls of your arteries. This force is generated as the heart pumps blood throughout the body. The measurement consists of two numbers, with the top number specifically referring to systolic blood pressure. This top number reflects the pressure within your arteries when your heart contracts and pushes blood out. Understanding this measurement is important for assessing cardiovascular health.
Understanding Systolic Blood Pressure
Systolic blood pressure represents the peak pressure exerted on the artery walls during the heart’s contraction phase, known as systole. It is the first and higher number in a blood pressure reading. For an adult, a normal systolic reading is below 120 millimeters of mercury (mmHg).
Readings between 120-129 mmHg with a diastolic pressure below 80 mmHg are considered elevated. Stage 1 hypertension is diagnosed when systolic pressure is 130-139 mmHg, or if the diastolic pressure is 80-89 mmHg. Stage 2 hypertension occurs when the systolic pressure is 140 mmHg or higher, or the diastolic pressure is 90 mmHg or higher. Blood pressure is commonly measured using a sphygmomanometer, which involves an inflatable cuff placed around the upper arm. The cuff inflates to temporarily stop blood flow, then slowly deflates while a healthcare provider listens for blood flow sounds to determine the systolic and diastolic pressures.
Lifestyle and Age-Related Factors
Many daily habits and the natural process of aging influence systolic blood pressure. A diet rich in sodium, often found in processed foods, can increase blood pressure by causing the body to retain water, thereby increasing blood volume. Conversely, insufficient potassium intake can hinder the body’s ability to excrete sodium, impacting blood pressure regulation.
A lack of regular physical activity contributes to higher systolic pressure, as does excessive alcohol consumption, which can lead to sustained hypertension. Smoking also causes increases in blood pressure and damages blood vessel walls, accelerating plaque buildup. Chronic stress can induce a surge in hormones that elevate heart rate and constrict blood vessels.
Obesity is a factor, as excess body fat can lead to insulin resistance and hormonal changes affecting blood pressure. As individuals age, large arteries become stiffer, which causes systolic blood pressure to rise. Genetic predispositions also play a role, making some individuals more susceptible.
Medical Conditions and Medications
Beyond lifestyle choices, certain underlying medical conditions can contribute to high systolic blood pressure. Kidney disease can impair the kidneys’ ability to regulate fluid and electrolyte balance, leading to increased blood volume and pressure. Both an overactive (hyperthyroidism) and underactive (hypothyroidism) thyroid can affect the cardiovascular system, causing the heart to work harder or beat faster.
Sleep apnea, a condition where breathing repeatedly stops and starts during sleep, can also elevate blood pressure. Tumors on the adrenal glands can cause an overproduction of hormones like adrenaline or aldosterone, which regulate blood pressure and can lead to hypertension. Coarctation of the aorta, a congenital narrowing of the major artery, forces the heart to pump against higher resistance, increasing systolic pressure.
Several common medications can also influence systolic blood pressure. Decongestants, nonsteroidal anti-inflammatory drugs (NSAIDs), certain antidepressants, and oral contraceptives can cause or worsen high blood pressure. These effects often stem from mechanisms such as blood vessel constriction or alterations in fluid balance.
Health Implications of High Systolic Blood Pressure
Sustained high systolic blood pressure can cause damage to arteries and other organs. This persistent force can weaken and narrow blood vessels, making them more susceptible to blockages. Over time, these arterial changes can lead to cardiovascular events.
High systolic pressure increases the risk of heart attack and stroke by damaging the arteries that supply blood to the heart and brain. It can also contribute to heart failure, where the heart muscle becomes less effective at pumping blood. Chronically elevated systolic pressure can impair kidney function, leading to kidney disease or failure. Other potential complications include vision loss due to damage to the delicate blood vessels in the eyes and peripheral artery disease, which affects blood flow to the limbs.