Does caffeine raise blood pressure?
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Yes, for a few hours. In people with hypertension, 200 to 300 mg of caffeine raised pressure by about 8/6 mmHg within the first hour, and it stayed up for at least 3 hours. Drinking coffee regularly has a much smaller long-term effect. Measure before your first cup.
Short term and long term
| Question | Result | Source |
|---|---|---|
| One dose of 200 to 300 mg, in people with hypertension | 8.1/5.7 mmHg higher within the first hour, lasting at least 3 hours | 5 trials, 2011 |
| Coffee for 2 weeks, in people with hypertension | No rise against a caffeine-free diet or decaf | 3 studies, 2011 |
| Regular caffeine pills, median 410 mg a day | 4.2/2.4 mmHg higher | 7 trials, 2005 |
| Regular coffee, median 725 mL a day | 1.2/0.5 mmHg higher | 18 trials, 2005 |
| Habitual coffee and later heart disease, in people with hypertension | No link found | 7 cohorts, 2011 |
Coffee raises your pressure clearly for a few hours, but the lasting effect is small. Caffeine on its own seems to do more than the caffeine in coffee.
Do regular drinkers adapt?
Only some of them do. In one trial, researchers gave healthy adults caffeine every day. After 5 days, half of them still had a blood pressure response to a new dose. How much someone drank each day didn’t predict how much tolerance they built. Even if you drink coffee every day, your morning cup can still raise your pressure.
How much is in a drink
| Drink, 12 fl oz | Caffeine |
|---|---|
| Regular brewed coffee | 113 to 247 mg |
| Energy drink | 41 to 246 mg |
| Black tea | 71 mg |
| Green tea | 37 mg |
| Caffeinated soft drink | 23 to 83 mg |
One large coffee can reach the 200 to 300 mg used in the trials. The FDA says about 400 mg a day isn’t generally tied to negative effects in most healthy adults. If you’re pregnant, breastfeeding or on certain medications, it advises checking with a clinician.
Energy drinks
They may do more than the caffeine alone. In a small trial, researchers compared 32 oz of energy drink with the same dose of caffeine on its own. After 6 hours, systolic pressure (the top number) was 4.7 mmHg above where it started with the energy drink, and 0.8 mmHg with caffeine alone.
What it means for your cuff
The American Heart Association advises no caffeine in the 30 minutes before measuring. In the trials above the rise lasted at least 3 hours, so you’ll get the cleanest number before your first cup. In the evening, measure before bed and note any late coffee or energy drink.
Take a home week of measurements, done the same way each day, so you can compare your average with the next one.
If you want to test your own response, take a few measurements before coffee and an hour after, on a few mornings. Don’t count the after-coffee numbers in your home average. If your average is high on mornings before coffee, that points to other causes, and the how-to lists them, biggest first.
6 sources
- Mesas AE et al., caffeine and coffee in hypertension, American Journal of Clinical Nutrition, 2011pubmed.ncbi.nlm.nih.gov
- Noordzij M et al., chronic intake of coffee and caffeine, Journal of Hypertension, 2005pubmed.ncbi.nlm.nih.gov
- Lovallo WR et al., incomplete tolerance to caffeine, Hypertension, 2004pubmed.ncbi.nlm.nih.gov
- Fletcher EA et al., high-volume energy drink against caffeine, Journal of the American Heart Association, 2017ahajournals.org
- US Food and Drug Administration, Spilling the Beans, how much caffeine is too much, 2024fda.gov
- American Heart Association, Toolbox Talks, Blood Pressure, preparing to measure, checked 2026heart.org
