Hi, I'm a nursing student and to be honest with you 140/90 and anything about is considered hypertension. However!!!! Before you freak out! How ok are you? Do you smoke? Do you drink coffee? What is your baseline BP? It's not like you went from 100/75 to 140/90 right? Stress and anxiety can greatly alter your BP! For instance, mine is usually 90/60 but I went to the Dr yesterday and it was 124/80. Wow can you say white coat syndrome lol!
I would chat with your dr about your BP readings, your baseline readings, your lifestyle and things you can do to decrease it. Because it isn't necessarily high to e an issue today, but higher blood pressures over time can potentially cause people problems. Your dr should be able to help you modify your diet (decrease salt & caffeine maybe) to get your readings a little lower!
But don't stress about it, it will only cause it to be high. In all honesty, 140/90 is very mild to the hypertension I see in the hospital. So try to keep it in perspective, your like on the low border of hypertension and it maybe be totally normal for your body. Everyone's body is different and ranges for BP are statistical reference ranges, there isn't a true black and white written in stone range of "normal" that would apply to everyone. Know what I mean?