What is the difference between systolic blood pressure and diastolic blood pressure? diastolic blood pressure represents the blood pressure of a healthy individual while systolic blood pressure represents the blood pressure of an unhealthy individual. systolic blood pressure measures the force of blood against the artery walls when the heart is contracting and diastolic blood pressure measures the force of blood against the artery walls between contractions. diastolic blood pressure measures the force of blood against the artery walls when the heart is contracting and systolic blood pressure measures the force of blood against the artery walls between contractions. systolic blood pressure represents the blood pressure of a healthy individual while diastolic blood pressure represents the blood pressure of an unhealthy individual.