Blood pressure measures the force exerted by circulating blood against artery walls. It is given as two numbers: systolic (the top number, pressure when the heart beats) and diastolic (the bottom number, pressure when the heart rests). A reading of 98/58 mmHg is on the low end of the normal range, often prompting concern about adequate blood flow, a state sometimes referred to as hypotension.
Defining Low Blood Pressure (Hypotension)
Low blood pressure, or hypotension, is clinically defined as a reading below 90 millimeters of mercury (mmHg) systolic and 60 mmHg diastolic for most adults. Although 98/58 mmHg is technically above this threshold, it falls significantly lower than the generally accepted healthy range of 90/60 to 120/80 mmHg. This reading indicates that both the heart’s pumping force (systolic 98) and the residual pressure in the arteries (diastolic 58) are consistently low, suggesting a reduced overall circulatory force. While not categorized as absolute hypotension, 98/58 mmHg is often treated as functionally low, especially if it represents a significant drop from a person’s typical reading or if it is accompanied by symptoms.
Common Causes and Contributing Factors
A reading of 98/58 mmHg can stem from various factors, ranging from daily circumstances to underlying health conditions. Dehydration is a frequent cause, as it reduces the total volume of circulating blood, decreasing the pressure against artery walls. Certain medications, particularly those treating hypertension like diuretics, alpha-blockers, and beta-blockers, are also known to lower blood pressure. Pregnancy often causes a temporary drop, usually during the first and second trimesters, due to the rapid expansion of the circulatory system. Hormonal disorders, such as hypothyroidism, can slow the heart rate and reduce the heart’s output, contributing to a lower reading.
In some cases, the drop is situational, known as orthostatic hypotension. This occurs when moving rapidly from sitting or lying down to standing, causing blood to pool in the legs because the nervous system fails to quickly compensate. More serious factors include heart issues, such as heart failure or a slow heart rate (bradycardia), which impair the heart’s ability to pump sufficient blood volume to maintain pressure.
Recognizing Associated Symptoms and Warning Signs
When blood pressure is low, the body’s organs, particularly the brain, may not receive enough oxygenated blood, leading to noticeable physical symptoms.
Mild Symptoms
Common signs associated with a reading of 98/58 mmHg include feeling lightheaded or dizzy, blurred or fading vision, and a generalized feeling of weakness or fatigue. Nausea or difficulty concentrating may also occur. These mild symptoms often improve quickly by sitting or lying down and elevating the feet.
Warning Signs
A low blood pressure reading can occasionally signal a more severe problem, requiring immediate medical attention. Warning signs of dangerously low blood pressure, often indicating the onset of shock, include rapid and shallow breathing, confusion, and cold, clammy, or pale skin. A weak and rapid pulse indicates the body is struggling to maintain adequate blood flow to vital organs. If these severe symptoms accompany a low reading, they represent a medical emergency.
Immediate Management and Lifestyle Adjustments
For mild and asymptomatic low blood pressure, several practical lifestyle adjustments can help maintain a stable reading and prevent symptomatic drops. Increasing fluid intake is one of the most effective immediate strategies, as this helps increase blood volume and, subsequently, blood pressure. Aiming to drink six to eight glasses of fluid daily is a good starting point, though fluid needs can increase with exercise or in warm weather.
A doctor may suggest a modest increase in sodium intake, as salt helps the body retain water, which aids in maintaining blood volume. However, this adjustment should only be implemented with medical guidance. To mitigate orthostatic drops, one should avoid sudden changes in body position, instead moving slowly from lying to sitting, and then pausing before standing.
Eating smaller, more frequent meals can prevent a significant drop in blood pressure that often occurs after large meals as blood is diverted to the digestive tract. Using simple physical maneuvers, such as crossing the legs while standing or sitting, can also help increase blood pressure by limiting blood pooling in the lower extremities.
If a low reading is persistent or accompanied by bothersome symptoms, consulting a healthcare provider is necessary to rule out any underlying medical causes and determine a personalized treatment plan.