High systolic/low diastolic pressure

I recently had my blood pressure checked and I forget exactly, but it was about 143/68 with a pulse of 55. I've read that this combination of high systolic and low diastolic is particularly bad, but I don't know why. I'm 26 years old and the perfect weight for my size. I haven't checked my blood pressure in almost a year, but I've never had a high reading before. Is this something I should be overly concerned about? I don't have health insurance, nor will I for some time. Is there anything in particular that I should be doing to bring down my systolic pressure only? Should I worry about the diastolic pressure, or just follow the normal recommendations for lowering BP. My diet has not been too good for the past year, and I haven't been getting much cardiovascular exercise. I've just recently improved my diet, started exercising again, and running 6 miles per week.

[kenkeith]

Pulse rate (difference systole and diastolic) is normal at 40 and above 60 may indicate hardening and/or abnormal narrowing of the vessels.  The heart is required to pump harder against the higher resistance and it the long term can cause heart related disorders.

You may not have any problem with an isolated or unsustained systole pressure greater than what is considered ideal or normal.  It is unlikely at your age to have hardening of the arteries (usually an older person's malady.

[markmsn10]

It's important to check your pressure after a good rest (say 5 minutes)  something as simple as walking around raises your systolic and doesn't raise diastolic.  Same thing with exercise; systolic will rise and diastolic stays the same or falls.  This is a normal response.  If checking your blood pressure when not fully relaxed, you will see high pulse pressures.  Also, anxiety will have the same effect.   Take a deep breath and relax.  Repeat a measurement after a few minutes.  Chances are that number will lower.

I will say that a pulse pressure of 40 is difficult to see.   Most of the time it will be between 40-55 and still be considered just fine.