What are the blood pressure requirements to pass the DOT physical?
Here are the medical guidelines according to the Federal Motor Carrier Safety Regulations (FMCSRs). Note that employers are allowed to impose more stringent medical requirements.
 A driver with a BP of less than 140 / 90 may be medically certified to drive for a two-year period.
 A driver with a BP of 140 – 159 systolic and /or a BP of 90-99 diastolic, has stage 1 hypertension, and may be medically certified to drive for a one-year period. Certification examinations should be done annually thereafter and should be at or less than 140/90.
 A driver with a BP of 160-179 systolic and/or a BP of 100-109 diastolic, has stage 2 hypertension, and is a candidate for antihypertensive drug therapy. The driver is given a one-time certification of three months to reduce his or her blood pressure to less than or equal to 140/90. Provided treatment is well tolerated and the driver demonstrates a BP value of 140/90 or less, he or she may be re-certified for one year from the date of the initial exam. The driver is certified annually thereafter.
 A driver with a BP at or greater than 180 systolic and / or 110 diastolic has stage 3 hypertension and is disqualified. The driver may not be qualified, even temporarily, until blood pressure is reduced to equal to or less than 140/90 and treatment is well tolerated. The driver may be certified for 6 months and biannually (every 6 months) thereafter if at recheck BP is equal to or less than 140/90.
Drivers with Type 1 or Type 2 diabetes, or kidney disease require treatment if their blood pressure rises above 130/80, since they already have a high risk of heart disease.

http://www.fmcsa.dot.gov/faq/what-basis-fmcsas-recommendations-regarding-high-blood-pressure