There are two numbers in blood pressure. Does a five point drop mean both numbers dropped five points?
What if the two numbers change by different amounts?
The systolic (first, larger) number is generally considered more important in diagnosing hypertension as it is more closely correlated with negative events, so I would assume the statement refers to the systolic figure. Both numbers are significant, though.
The systolic (first) number represents pressure when your heart pushes blood out into the arteries. The diastolic number represents blood pressure when your heart draws blood in from the veins.
Picture your heart as a bellows-style air pump when you squeeze it, air is forced into the the outgoing hose (arteries) temporarily increasing the pressure. When you release it, air is drawn in from the incoming hose (veins in the body, cause it’s a closed loop) while special valves keep it from being drawn back from the outgoing hose. This cycle is why you have a pulse.
That’s more info than you really need, but it does put the numbers into perspective.
What does it mean? It means whoever said that wasn’t being real precise.
Now if they’d said “my systolic blood pressure dropped by 10 points”, then it’d be clearer.
Blood pressure is very dynamic, changing quickly from minute to minute at times. And it’s pretty typical for the systolic and diastolic pressures to change by different amounts. They are in no way locked rigidly together.
Depending on the context, it can very well mean “I’m a bit calmer now, thank-you.”
Mine will drop 5 or 10 between the time the intake technician takes a reading and the end of the appointment. Early morning appointments occasionally more.