✔ 最佳答案
age like 20, (adult), BP should be around/under 120/80.
boys and girls are usually the same, it's more depend on weight and sometimes height too.
tiny people usually have lower blood pressure.
if BP is too high, something like 140/90 or higher, that's high blood pressure, would cause stroke or some other serious health problem;
if BP is too (very) low, would cause dizziness, but won't cause serious health problem.
younger age would have lower blood pressure, which is normal.
like my case, i am 28 girl w/ normal high and weight, and my BP is usually 100/70 after meal, and it's still normal.