Hypertension

Hypertension means high blood pressure. This generally means:

• Systolic blood pressure is consistently over 140 (systolic is the "top" number of your blood pressure measurement, which represents the pressure generated when the heart beats)
• Diastolic blood pressure is consistently over 90 (diastolic is the "bottom" number of your blood pressure measurement, which represents the pressure in the vessels when the heart is at rest)
  

 

More

http://dir.yahoo.com/Health/Diseases_and_Conditions/Hypertension/

http://www.nlm.nih.gov/medlineplus/highbloodpressure.html