How Bad Is This BP ?

I work at a pharmacy and there is one of those blood pressure machines that I use often to check my blood pressure. Usually, these are the results: Diastolic - 140 Systolic - 75 BPM - 55 I know that a healthy blood pressure is 120/80, so the 140 concerns me. Is that too high, and should I see a doctor? I am 21 years old and in otherwise good health, exercise regularly and follow a moderately healthy diet. I do eat too much sodium, and I know that s something I need to work on. I think that my heart rate is low because I do a lot of cardio training, and HIIT (high intensity interval training).