Blood pressure is a measurement of the force exerted by circulating blood against the walls of the body’s arteries, the major blood vessels. This measurement acts as a simple indicator of overall health, offering a window into how effectively the heart and blood vessels are working. A reading outside of the optimal range can signal potential health issues, making regular monitoring and interpretation a valuable practice for maintaining long-term health.
Deconstructing Blood Pressure Readings
A blood pressure reading is always expressed as two numbers, written as a fraction like 120/80, measured in millimeters of mercury (mmHg). The first and higher number is the systolic pressure, which records the force in the arteries when the heart contracts and pushes blood out. This represents the maximum pressure the blood vessels experience during the cardiac cycle.
The second and lower number is the diastolic pressure, which measures the force in the arteries when the heart is at rest, between beats. Both the systolic and diastolic values are significant because they reflect different aspects of heart function and vascular health. The systolic number is often considered a stronger predictor of cardiovascular risk in adults over 50.
Interpreting 105/65
The reading 105/65 mmHg falls comfortably within the optimal or normal range for most healthy adults. Medical guidelines define a normal blood pressure as less than 120 mmHg systolic and less than 80 mmHg diastolic. This reading is below the threshold for elevated blood pressure, which begins at 120/80 mmHg.
The 105/65 reading is often described as low-normal, indicating an excellent cardiovascular profile. This low pressure suggests that the heart is working efficiently and that the arteries are flexible, offering little resistance to blood flow.
This reading is well above the clinical definition of hypotension, or low blood pressure, which is typically defined as 90/60 mmHg or lower. A healthy reading like this generally suggests a lower risk for future complications like heart attack or stroke.
When Low-Normal Becomes Hypotension
While 105/65 is generally a healthy reading, any low-normal pressure can become problematic if it causes symptoms or drops further. True hypotension is defined by a reading of 90/60 mmHg or less, but the presence of symptoms often determines if a low reading requires attention. A reading above the clinical threshold can cause distress if it represents a significant, sudden drop from a person’s usual pressure.
Symptoms of excessively low blood pressure occur because the brain and other organs are not receiving enough blood flow. These symptoms can include:
- Lightheadedness
- Dizziness
- Weakness
- Blurred vision
- Nausea
- Profound fatigue
In severe cases, very low pressure can lead to fainting (syncope) or a life-threatening state of shock.
Several factors can cause a healthy low-normal reading to dip further into symptomatic hypotension. Common non-disease-related causes include dehydration, certain medications (such as those for high blood pressure or depression), or temporary drops when standing up too quickly (orthostatic hypotension) or after eating a large meal. More serious causes involve underlying conditions like severe infection, internal bleeding, heart problems, or endocrine disorders.
Maintaining Healthy Blood Pressure
Since a reading of 105/65 is excellent, the focus shifts to maintaining this healthy state through consistent lifestyle habits. Hydration is a simple yet powerful tool, as adequate fluid intake directly supports healthy blood volume, helping to keep pressure stable. This is especially important for those with naturally low-normal readings, as dehydration could easily push the pressure lower.
Dietary choices should emphasize a balance of nutrients, including a sufficient but not excessive intake of sodium. Unlike those with high blood pressure who must strictly limit salt, individuals with lower pressure may need to ensure they are not restricting sodium too severely.
Regular physical activity, such as aiming for 150 minutes of moderate-intensity exercise weekly, also contributes to healthy circulatory function and vessel flexibility. Consistent monitoring, even when readings are good, helps establish a reliable baseline and allows for the quick detection of any significant, symptomatic drops.