I can understand your concern. if a person has such a high pressure, its a medical emergency.
also a known hypertensive is at a risk of blood pressure shooting high,
so if you are a hypertensive , take your blood pressure medication daily and without fail.
lower your salt intake in the diet.
avoid pickles, papads etc. as they have high amount of salt. avoid chinese foods as they use a soy sauce which has a very high level of sodium.
drink lots of water and use low sodium salt in cooking.
practicing yoga, pranayama and meditation will also help in keeping blood pressure under control.
Dr. Anil kumar jain