Yes, coffee raises blood pressure for a few hours, about 8 points on the top number after one to two cups in people with high blood pressure, but over weeks of daily coffee the rise shrank to about 1 point.
People often expect me to tell them to give up coffee. For most of them, I don't.
In the first few hours after a cup, caffeine pushes your pressure up, and a home cuff will show it. In long-term studies, coffee drinkers had blood pressure much like people who skip it. What matters most is when you drink it compared with when you measure.
The book's grade: UNLIKELY TO HELP blood pressure directly. Coffee is neutral for blood pressure, and most people have no reason to give it up. The exception is severe, uncontrolled high blood pressure.
How much does caffeine raise blood pressure after a cup?
Blood pressure is measured in millimeters of mercury (mmHg), which most people call points.
In people with high blood pressure, 200 to 300 mg of caffeine raised the top number (systolic) about 8 points and the bottom number (diastolic) about 6 (review of coffee in people with high blood pressure). That's about one to two 12-ounce cups of brewed coffee.
- The rise started within an hour.
- It lasted at least 3 hours.
On average, that's the difference between a reading of about 130/78 before your coffee and 138/84 an hour after it. Your own rise may be bigger or smaller.
Does coffee cause high blood pressure over time?
For most people, it doesn't seem to. The short-term rise fades for many people once coffee is a daily habit.
- Daily coffee in trials: in trials that ran a week or longer, regular coffee raised the top number only about 1 point. Caffeine pills, at a median of 410 mg a day, raised it about 4 (review of coffee and caffeine trials).
- Your chance of getting high blood pressure: in long-term studies of almost 200,000 people, one or two cups a day showed no link, and three or more cups went with a slightly lower risk (review of long-term coffee studies). Studies that follow people over time can show a pattern. They can't prove that coffee caused it.
Is coffee bad for high blood pressure?
Usually not. The exception is pressure that is severe and not under control.
The 2025 American Heart Association and American College of Cardiology guideline gives two limits (2025 AHA/ACC guideline):
- If you have high blood pressure, keep caffeine under 300 mg a day.
- If your pressure is severe and uncontrolled, have no more than 1 cup a day.
One study backs up that caution. It followed 18,609 Japanese adults for about 19 years. People with severe high blood pressure who drank two or more cups a day were about twice as likely to die of heart disease or stroke (Japanese study of coffee and blood pressure). The link didn't appear at lower blood pressure levels. A single study like this can't prove coffee was the cause.
How much caffeine is in your cup?
The FDA lists these amounts (FDA caffeine guide):
- Brewed coffee: 113 to 247 mg per 12 ounces
- Black tea: 71 mg per 12 ounces
- Green tea: 37 mg per 12 ounces
- Caffeinated soda: 23 to 83 mg per 12 ounces
- Decaf coffee: 2 to 15 mg per 8 ounces
A strong 12-ounce coffee can hold close to 250 mg. That means the guideline's 300 mg limit can arrive partway through your second mug. If you're pregnant, trying to get pregnant or breastfeeding, the FDA suggests asking your health care provider whether you should limit caffeine.
Will quitting coffee lower blood pressure?
Probably only a little. In one older trial, 45 healthy adults who drank 5 cups a day switched to decaf for 6 weeks. Their top number on a portable monitor fell about 1.5 points (decaf trial).
Grade for decaf in place of regular coffee: PLAUSIBLE (weak evidence). It's one small, old trial. Priority: Optional extras.
If you love your morning cup, keep it and put your effort elsewhere. Cutting sodium by about 1,700 mg a day lowered the top number about 5 points (review of salt reduction trials). My ranked list of what lowers blood pressure shows where coffee sits next to salt, walking and weight.
Energy drinks act differently
Energy drinks raised blood pressure more than coffee did, and caffeine doesn't seem to explain all of it.
- One drink: in 15 studies, one energy drink raised the top number about 4.4 points and the bottom about 2.7. Drinks with 200 mg of caffeine or more raised the top number about 6.4 (review of energy drink studies).
- 32 ounces in an hour: in a trial of 34 healthy young adults, 9 people on one energy drink and 8 on another reached a top number of 140 or higher, compared with 2 on a placebo drink. The drinks also lengthened the QT interval, the heart's electrical recharge time (energy drink trial).
- Same caffeine, different result: 18 healthy adults got 320 mg of caffeine either way. Six hours later, the top number was still up about 4.7 points after an energy drink, but less than 1 point after a caffeine-only drink (caffeine comparison trial).
Grade for energy drinks: POSSIBLY HARMFUL (might raise blood pressure). Priority: Skip. Avoid them entirely if you have high blood pressure, a heart-rhythm problem or take a stimulant medicine. Caffeine pills and pure caffeine powder carry the same grade.
Can I drink coffee before taking my blood pressure?
Caffeine in the past few hours raised the top number of a single reading by about 3 to 14 points across many studies (review of reading errors).
- No caffeine for at least 30 minutes before a reading. Treat 30 minutes as the minimum, since the rise can last 3 hours.
- Take your morning readings before breakfast and before your first cup.
- If your evening readings run high, write down when you had your last coffee, tea or soda.
- Judge the average, not one number. A home week means two readings in the morning and two in the evening for 7 days. My guide to taking your blood pressure at home walks through each step.
I use 130/80 as the goal throughout the book so the numbers line up. Your doctor may use 140/90, and that isn't wrong either.
When to call your doctor
- A reading over 180/120: wait at least a minute and check again. If it's still that high and you have chest pain, shortness of breath, weakness, a change in vision, a sudden severe headache or trouble speaking, call 911. With no symptoms, contact your doctor's office as soon as possible (the on-call line after hours). If you can't reach a person or get seen that day, go to urgent care.
- A racing or skipping heartbeat, or fainting: get medical care right away.
- On blood pressure pills? Never stop or change one on your own because of a high reading after coffee. Bring your log to your doctor instead.
Bottom line
Coffee raises blood pressure for a few hours, about 8 points on top after one to two cups in people with high blood pressure. Over weeks, the rise shrinks to about 1 point for most people, and coffee drinkers aren't more likely to develop high blood pressure. Keep caffeine under 300 mg a day if you have high blood pressure, and stick to 1 cup a day if yours is severe and uncontrolled. Take your readings before your first cup, and leave energy drinks on the shelf.
Questions people ask
Does caffeine raise blood pressure?
Yes, for a few hours. In people with high blood pressure, 200 to 300 mg of caffeine raised the top number about 8 points and the bottom about 6, starting within an hour and lasting at least 3 hours. Over weeks of daily coffee, the rise shrank to about 1 point in trials.
Is coffee bad for high blood pressure?
For most people, no. The guideline says to keep caffeine under 300 mg a day if you have high blood pressure, and no more than 1 cup a day if your pressure is severe and uncontrolled.
Can coffee cause high blood pressure?
The long-term studies say probably not. In almost 200,000 people, one or two cups a day showed no link to getting high blood pressure, and three or more cups went with a slightly lower risk.
How long should I wait after coffee to check my blood pressure?
At least 30 minutes, and longer is better. The rise after a cup lasted at least 3 hours in the studies, so take your morning readings before your first cup.
Does decaf coffee raise blood pressure?
Decaf has only 2 to 15 mg of caffeine per 8 ounces, and it may lower blood pressure slightly. In one small trial, heavy coffee drinkers who switched to decaf for 6 weeks saw their top number fall about 1.5 points. The book grades decaf PLAUSIBLE (weak evidence), an optional extra.
What else is in your cup, graded
Coffee is one of dozens of foods, drinks, habits and supplements I grade in my upcoming book, Your Blood Pressure by the Numbers, each with a real number. If you like hot drinks, you'll want the tea verdicts. Hibiscus tea is PLAUSIBLE (mixed evidence), with about 7 points off the top number in pooled trials that disagree a great deal, and black or green tea is PLAUSIBLE (weak evidence). The book also grades isometric handgrip training, SUPPORTED for office readings. It's coming soon.
The drink that matters more for blood pressure is the one in the evening. Read what alcohol does to blood pressure next.