Understanding blood pressure and heart rate can be confusing, as there is some variance to what the medical communty defines as normal. Different physicians or health care practicioners may give slightly different answers, and while the answers may be somewhat distinct, they are usually within a range of defined parameters.
What is Blood Pressure?
Blood pressure is a term used to describe the force that is exerted on the walls of blood vessels as blood is circulated in the body. Blood pressure is essentially two distinct measurements reported as one reading. The first measurement is the systolic pressure and represents the force within the blood vessels with each contraction of the heart. The second measurement is the diastolic reading and represents the force inside the blood vessels between beats of the heart (that is while the heart is resting). The recorded measurement is written as systolic blood pressure/diastolic blood pressure or 120/80 for example.
What is Normal Blood Pressure?
While 120/80 is considered to be normal blood pressure, this number can vary from individual to individual. Blood pressure is also a dynamic process that changes somewhat from second to second, as the body reacts to changes in position, mood, movement and environmental stimuli.
Hypertension or high blood pressure is classified in stages with pre-hypertension being systolic readings between 120-139 and diastolic readings of 80-89. Stage I hypertension readings are a systolic measurement in the 140-159 range with diastolic readings of 90-99. Stage II hypertension is classified as having diastolic readings above 160 and systolic readings greater than 100.
Hypotension is blood pressure than is lower than 115/75. People can run a blood pressure lower than the normal 120/80 and be perfectly fine as long as they have no dizziness, lightheadedness, fainting or seizures. Hypotension that is accompanied by symptoms needs to be evaluated by a physician to determine the cause.
Heart rate is the number of beats that occur within 60 seconds of time. The normal heart rate is 60-80 bpm (beats per minute), although this can vary with the individual. Like blood pressure, it is dynamic, responding to changes in position, environment, mood and movement. Heart rates below 60 bpm are called bradycardia and may be normal in well-conditioned individuals and athletes. Certain medications can decrease the heart rate as well. A physician should evaluate unexplained bradycardia that is sustained or that is accompanied by fainting, dizziness, shortness, of breath, chest pain or discomfort, nausea or sweating.
Tachycardia is the term for a rapid heartbeat above 100 bpm in adults. When the heart beats rapidly, the beats become less efficient and deliver a smaller volume of blood with each stroke. This is due to the heart having less time to fill with blood between beats. Tachycardia may be a response to fever or to changes in blood pressure, or may be due to disruptions in the electrical impulses of the heart. Heart rates that elevate during exercise are normal adaptive responses to an increased need for oxygen by the body and are healthy.
As previously mentioned, wide variances can occur in both heart rate and blood pressure without being abnormal. However, a physician should evaluate any change in heart rate or blood pressure that is accompanied by symptoms.