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Short answer: Yes, caffeine raises blood pressure for a few hours. In people with high blood pressure, 200 to 300 mg of caffeine raised it by about 8/6 mm Hg on average, starting within an hour and lasting at least 3 hours. Over the longer term the effect is smaller: regular drinkers build up partial tolerance, and when caffeine comes from coffee, trials found only a small rise of about 1 mm Hg. Habitual coffee drinking has not been linked to a higher risk of high blood pressure in large studies. If you have high blood pressure, ask your provider how much caffeine is right for you.
MedlinePlus lists raising blood pressure among the effects of caffeine (MedlinePlus). But how much, for how long, and does it matter for people who drink coffee every day? Here is what the research shows, including what it means if you already have high blood pressure and how to keep caffeine from skewing your readings.
What you'll learn
- How much and how long caffeine raises blood pressure
- Why regular coffee drinkers see a smaller effect
- Whether coffee is linked to high blood pressure over time
- What to do if you have high blood pressure, and how to measure it accurately
The short answer: yes, for a few hours
A meta-analysis of studies in people with high blood pressure found that 200 to 300 mg of caffeine, roughly two to three 8-ounce cups of brewed coffee at about 95 mg each (USDA FoodData Central), raised systolic blood pressure (the top number) by 8.1 mm Hg and diastolic blood pressure (the bottom number) by 5.7 mm Hg on average. The rise appeared within the first hour and lasted at least 3 hours (Mesas et al., 2011). That timing fits how caffeine works in the body: it peaks in your blood within about an hour, and you may feel it for 4 to 6 hours (MedlinePlus). For more on timing, see how long caffeine stays in your system.
Why regular coffee drinkers see a smaller effect
The body adapts to regular caffeine. In an early study of people who did not normally use caffeine, tolerance to its effects on blood pressure developed almost completely within the first 1 to 4 days of daily use (Robertson et al., 1981). Tolerance is not the same for everyone, though. Later research found that only about half of regular caffeine consumers become tolerant to the blood pressure effect in laboratory tests. In a trial of 85 adults, people with low tolerance still had higher blood pressure through the day, about 2.8/2.2 mm Hg while awake, after a week of 300 mg a day (Farag et al., 2005).
Coffee vs caffeine pills
A meta-analysis of 16 randomized trials lasting at least a week, with 1,010 participants, found different results depending on the source (Noordzij et al., 2005):
| Source in the trials | Typical intake | Average change in blood pressure |
|---|---|---|
| Caffeine (pills or capsules) | Median 410 mg a day | +4.16 / +2.41 mm Hg |
| Coffee | Median 725 mL (about 3 cups) a day | +1.22 / +0.49 mm Hg |
The authors concluded that regular caffeine raises blood pressure, but when it comes from coffee, the effect is small (Noordzij et al., 2005). In people with high blood pressure, three studies of two weeks of coffee found no rise in blood pressure compared with a caffeine-free diet or decaf (Mesas et al., 2011).
Does coffee cause high blood pressure?
Large long-term studies do not show that. A dose-response meta-analysis of 4 prospective studies with 196,256 people found that drinking one or two cups of coffee a day was not linked to a higher risk of developing high blood pressure, and three or more cups a day was linked to a slightly lower risk (D'Elia et al., 2019). In people who already have high blood pressure, 7 cohort studies found no link between habitual coffee drinking and a higher risk of heart disease (Mesas et al., 2011). These are observational studies, so they show associations rather than cause and effect, and they are about coffee, not energy drinks or caffeine supplements.
If you have high blood pressure
- Ask your provider how much caffeine is right for you, especially if your blood pressure is not yet under control or you take blood pressure medicine.
- Watch the dose. The biggest short-term rises were seen with 200 to 300 mg at once (Mesas et al., 2011). Spreading caffeine out, or choosing smaller cups, keeps each dose lower. See how much caffeine is in a cup of coffee.
- Consider decaf or lower-caffeine drinks. See does decaf coffee have caffeine.
- Cut back gradually if you decide to reduce caffeine, to avoid withdrawal headaches. See caffeine withdrawal.
- Know the general limit. For most healthy adults, up to 400 mg a day is not generally associated with negative effects (FDA); your provider may advise less.
How to keep caffeine from skewing your blood pressure reading
Because caffeine raises blood pressure for a while, it can affect your reading. MedlinePlus advises not taking your blood pressure within 30 minutes of having caffeine, a meal or tobacco, or right after exercise, and resting for at least 5 minutes before the measurement (MedlinePlus). If you check at home, take your reading before your morning coffee or at least 30 minutes after it.
Common myths (quick reality check)
Myth: Coffee always causes high blood pressure. Reality: Caffeine raises blood pressure for a few hours, but habitual coffee drinking has not been linked to a higher risk of developing high blood pressure in large studies.
Myth: If you drink coffee every day, caffeine has no effect on your blood pressure. Reality: Tolerance is incomplete for many people. About half of regular consumers still showed a blood pressure response in lab tests.
Myth: Caffeine pills and coffee have the same effect. Reality: In trials, caffeine pills raised blood pressure more than coffee did, about 4/2 mm Hg vs 1/0.5 mm Hg.
Frequently asked questions (FAQ)
Does caffeine raise blood pressure?
Yes, temporarily. In people with high blood pressure, 200 to 300 mg of caffeine raised it by about 8/6 mm Hg on average for at least 3 hours. The effect is smaller in many regular coffee drinkers.
How long does caffeine raise blood pressure?
The rise starts within the first hour and lasted at least 3 hours in studies of people with high blood pressure.
Does coffee raise blood pressure if you drink it every day?
Usually only a little. Trials of daily coffee found an average rise of about 1 mm Hg in systolic pressure, though some people do not build up full tolerance.
Can I drink coffee if I have high blood pressure?
Many studies found no link between habitual coffee and heart disease risk in people with high blood pressure, but ask your provider how much caffeine is right for you.
Does decaf coffee raise blood pressure?
In people with high blood pressure, two weeks of regular coffee did not raise blood pressure compared with decaf. Decaf contains only a small amount of caffeine.
Should I avoid caffeine before checking my blood pressure?
Yes. MedlinePlus advises not measuring within 30 minutes of having caffeine, and resting at least 5 minutes before the reading.
Related guides
- How long does caffeine stay in your system?
- How much caffeine is in a cup of coffee?
- Does decaf coffee have caffeine?
- Caffeine withdrawal: how long it lasts and how to ease it
- Why does coffee make me tired?
Disclaimer and when to seek help
This article is for general education and is not medical advice. These statements have not been evaluated by the Food and Drug Administration. Our products are not intended to diagnose, treat, cure, or prevent any disease. If you have high blood pressure, a heart condition or anxiety, are pregnant or breastfeeding, or take medication, talk to your health care provider about caffeine.
References
- Mesas AE, Leon-Muñoz LM, Rodriguez-Artalejo F, Lopez-Garcia E. "The effect of coffee on blood pressure and cardiovascular disease in hypertensive individuals: a systematic review and meta-analysis." American Journal of Clinical Nutrition, 2011;94(4):1113-1126. doi:10.3945/ajcn.111.016667
- Noordzij M, et al. "Blood pressure response to chronic intake of coffee and caffeine: a meta-analysis of randomized controlled trials." Journal of Hypertension, 2005;23(5):921-928. doi:10.1097/01.hjh.0000166828.94699.1d
- Robertson D, et al. "Tolerance to the humoral and hemodynamic effects of caffeine in man." Journal of Clinical Investigation, 1981;67(4):1111-1117. doi:10.1172/jci110124
- Farag NH, et al. "Caffeine tolerance is incomplete: persistent blood pressure responses in the ambulatory setting." American Journal of Hypertension, 2005;18(5):714-719. doi:10.1016/j.amjhyper.2005.03.738
- D'Elia L, et al. "Coffee consumption and risk of hypertension: a dose-response meta-analysis of prospective studies." European Journal of Nutrition, 2019;58(1):271-280. doi:10.1007/s00394-017-1591-z
- MedlinePlus (U.S. National Library of Medicine). "Caffeine".
- MedlinePlus (U.S. National Library of Medicine). "Blood pressure measurement".
- U.S. Department of Agriculture. FoodData Central (SR Legacy: coffee, brewed).
- U.S. Food and Drug Administration. "Spilling the Beans: How Much Caffeine Is Too Much?" Content current as of August 28, 2024.
