Stress

• Stressful situations can cause your blood pressure to increase, at least temporarily. Your body produces a surge of stress hormones that cause your heart to beat faster and blood vessels to constrict.
  
  

Smoking

• Smoking increases risk for heart disease and stroke for people who already have hypertension. It hasn't been proven to lead to developing hypertension. But, smoking just one cigarette can cause an immediate jump in blood pressure from 5 to 10 mm Hg.
  
  

Alcohol

• People who are heavy drinkers are 1.5 to 2 times more likely to increase the frequency in temporarily high blood pressure. According to the Mayo Clinic, if heavy drinkers cut back to moderate drinking, they can lower their blood pressure reading by 2.5 to 4 mm Hg.
  
  

Caffeine

• Drinking caffeinated beverages can cause a brief spike in blood pressure. Try taking your blood pressure about 30 minutes after drinking a cup of coffee or soda and see the difference. This can help you gauge if your blood pressure is sensitive to caffeine intake.
  
  

Medications

• Some prescription drugs and over-the-counter medications can cause temporary high blood pressure. Read the labels or talk to your doctor if you are concerned with brief spikes in your blood pressure.