Do I really have high blood pressure……?

I’m 13 and I’m very thin. I don’t feel that I get dizziness, headache, nauseous, or any of those high blood pressure symptoms. However, I just had a health check. They said that my blood pressure is pretty high D: Very high for my age. I was slightly anxious during the check-up though…. Do I really have high blood pressure? :/ I think I’m alright at doing sports, I don’t get too worn-out or anything.

This is just what worries me.
Even if I do have it, what can I do to lower the blood-pressure?

Thank you.
They said it’s not normal for me to get such a high blood pressure. They think anxiety caused it, but I don’t agree. I’m not saying that they’re lying – but they are unsure themselves.
BTW my blood pressure is reading is 137/74

heart rate – 95/min

Ah….

How many times that they check your blood pressure?

The right protocol would be like this (digital device is less accurate than the mercury):
Patient from walking/doing something else like running, yelling, etc should be delayed a while from checking the blood pressure. If checked, the result is high, another check need to be performed at least 1 minute from before. The place must be a quiet.

Panic and stress increases blood pressure, make sure you are relaxed.

Lower high blood pressure simply by exercise regurarly and eating healthy foods (fruits + vegetables).