My blood pressure is 156 over 53 what causes that ans is it a danger
Recheck it. You don't normally diagnose it over one or even two measurements. Was this done by a machine? Usually a person would not read an odd number (53).
The 156 is high. It can vary by age.
Yes it can be dangerous. High blood pressure can cause damage to the kidneys, eyes, lead to stroke or heart attack.
See your doctor for treatment. In some cases you may need medications, in others, changes in diet/loss of weight.
Hope it helps.