I have a headache. my blood pressure was 166 over 110 checked it little later it was little bit better but still close to that i am 51 is that danger?

Hypertension?: Your BP readings are high but they need to be confirmed before you start taking any medication. You should get your BP checked at rest(when you are fully relaxed) and do this on 3 different days. If the BP remains above 130/85, you should seek medical attention for starting on medical treatment. There are many good medicines which can use to bring down your BP to a desired level of <120/80 mm