Coffee can cause temporary blood pressure spikes in people with and without hypertension (high blood pressure). If you have high blood pressure, talk to a healthcare provider to get recommendations on coffee consumption.

Coffee Spikes Blood Pressure Short-Term

The short-term effects of coffee on blood pressure are:

• The systolic (top number) blood pressure rises by 3 to 14 mmHg
• The diastolic (bottom number) blood pressure rises by 4 to 13 mmHg.

Example: A typical reading of 120/80 may rise to 134/93 after drinking coffee.

Coffee is a stimulant that increases brain and nervous system activity. It impacts blood vessels and the heart within 30 minutes to two hours after consumption:

• Coffee enters the bloodstream: Once in the bloodstream, coffee interacts with hormones, brain receptors, and neurotransmitters.
• Coffee causes a blood vessel response: The response narrows arteries and veins, raising blood pressure.
• Coffee triggers a fight-or-flight response: it increases heart rate and blood pressure.

Factors that Impact How Much Coffee Affects Your Blood Pressure

Factors in how much coffee can affect your blood pressure include:

• Age: Caffeine impacts younger people more than those who are older. In one study, adolescents consistently had more significant increases in blood pressure than adults.
• Sex: Some research suggests that men metabolize caffeine faster than women do.
• Caffeine source: Coffee contains more caffeine than black or green tea. However, sodas and energy drinks also have caffeine and similar compounds, such as taurine and guanine.
• Coffee types and brewing method: The strength of different types of coffee beans and preparations (e.g., drip coffee versus espresso) can vary.
• Tolerance: After about 15 days of daily use, caffeine’s effects flatline and start to decrease, and you need more coffee to get the same effect.
• Smoking: Nicotine speeds up the metabolism, increasing caffeine’s effect on blood pressure.
• Pregnancy: Pregnant people should limit caffeine to 200 milliliters (ml) daily. Developing fetuses cannot metabolize caffeine, making it unsafe for pregnant people to drink in excess.
• Heart disease: A temporary blood pressure boost from caffeine may be more pronounced and less safe in those with cardiovascular (heart or blood vessel) diseases. 

Can You Drink Coffee if You Have High Blood Pressure?

Though coffee causes short-term increases in blood pressure, it doesn’t raise the risk of chronic high blood pressure. You can consume caffeine with high blood pressure, but much depends on your blood pressure and whether you’re a regular coffee drinker.

If your blood pressure is very high, be mindful of your caffeine consumption. In one study, one or two additional cups of coffee daily doubled the risk of cardiovascular disease, heart attack, or stroke in coffee drinkers with stage 2 and 3 hypertension. Researchers did not see this effect in those with normal, elevated, or stage 1 hypertension.

Moderate coffee consumption—one to three cups a day—may benefit the heart in people who drink coffee regularly. A multicenter study of 8,780 Brazilian adults between 35 and 74 found that moderate coffee drinkers were at less risk for high blood pressure than nondrinkers.

How Much Coffee Is Too Much?

Health authorities say that 400 mg or less of caffeine (about three or four 12-ounce (oz) cups of coffee) per day is safe for healthy adults. For adolescents (ages 12 to 18), this amount is 100 mg (one 12 oz cup), and it’s 2.5 mg per kilogram (kg) (about 2.2 pounds) of body weight in those under 12.

Drinking more than the recommended or “safe” amount can impact your health and can cause symptoms such as:

• Anxiety
• Elevated heart rate and blood pressure
• Headache
• Heart palpitations (irregular or “fluttering” heartbeats)
• Indigestion
• Insomnia (difficulty sleeping)
• Jitters, shaking
• Nausea

Considerations for Checking Your Blood Pressure At Home

When taking your blood pressure at home, keep these factors in mind:

• Before your test: Avoid smoking, coffee, or caffeinated beverages, and exercise for at least 30 minutes before testing your blood pressure. Be sure to empty your bladder.
• The cuff: Place it in the middle of the upper arm; don’t place it over clothing. Sit and rest quietly without a phone or screen for at least five minutes before starting.
• Your posture: While taking your blood pressure, stay seated with your back straight and feet flat on the floor. Support your arm with a flat surface, and place the cuff at the level of your heart.
• Timing: Take your blood pressure measurements at the same time every day and record your results. For accuracy, take a second blood pressure measurement one minute after the first.    

You’ll need a blood pressure monitor for at-home checks. Many types are available, but the American Heart Association (AHA) recommends an automatic, cuff-style upper arm monitor. Ensure it has been validated; talk to a healthcare provider or pharmacist about your options.

Though home blood pressure monitors are effective, a healthcare provider can provide more accurate and conclusive results. Contact a healthcare provider if your readings are much higher or lower than expected.