This is perhaps one of the common questions among java lovers and coffee noobs alike.
Many people know the effects of caffeine on the body. Some of them are positive, like added concentration and stronger mental performance, alertness and awake-ness, healthy glowing skin, boost in metabolism, and a happy disposition.
But going overboard with your caffeine fix could sometimes lead to adverse effects, including jitters, anxiety, and palpitations.
And this leads some people to ask whether caffeine also raises blood pressure.
This is an important question because 80 percent of Americans drink coffee every day and about 90 percent of people worldwide consume caffeine in one product or another. More importantly, high blood pressure can cause strokes or heart attacks.
So what’s the verdict?
The jury’s pretty much out on this one.
According to Mayo Clinic: 
Caffeine can cause a short, but dramatic increase in your blood pressure, even if you don't have high blood pressure. It's unclear what causes this spike in blood pressure. Some researchers believe that caffeine could block a hormone that helps keep your arteries widened. Others think that caffeine causes your adrenal glands to release more adrenaline, which causes your blood pressure to increase.
Recent studies, however, have repeatedly reported that caffeine doesn’t necessarily lead to an increased blood pressure, nor does it up the risk for cardiovascular diseases like high blood pressure, heart disease and cardiac arrest.
Verywellhealth.com also states a well-known study stating that there’s no direct link between caffeine and a rise in blood pressure: 
One very well-known study examined more than 85,000 women over a ten-year period and found that there was no increased risk of these diseases, even in women who drank more than six cups of coffee per day.
The Joint National Committee on Hypertension likewise reports that there’s indeed no evidence that caffeine leads to high blood pressure.
And here’s another silver lining: 
Some people who regularly drink caffeinated beverages have a higher average blood pressure than do those who drink none. Others who regularly drink caffeinated beverages develop a tolerance to caffeine. As a result, caffeine doesn't have a long-term effect on their blood pressure. It seems that caffeine has a stronger blood pressure increasing effect in men who are older than 70 or who are overweight.
It has become so accepted that caffeine raises blood pressure, that doctors advise avoiding caffeine before having your blood pressure checked because it may raise it enough to falsify test results.
But what is the evidence for caffeine raising blood pressure?
A 1987 Italian study actually found that caffeine lowers blood pressure.  In this study, researchers from the United States and Switzerland studied 15 volunteers who didn't have high blood pressure and were nonsmokers. Only six habitually drank coffee. Harvard says:
“The researchers monitored each volunteer's blood pressure, heart rate, and sympathetic nervous system under four conditions: before and after drinking a triple espresso, before and after drinking a decaffeinated triple espresso, before and after receiving 250 mg of caffeine by intravenous injection, and before and after an intravenous placebo (salt solution).”
A triple espresso did raise blood pressure readings except in the habitual coffee drinkers. In those who didn't drink coffee, it raises systolic readings 13 mm Hg on average and diastolic by 7 mm Hg.
Harvard Medical School says:
“Espresso is strong stuff, but an intravenous slug of caffeine should be even more potent. Indeed, blood caffeine levels rose to the same degree after the caffeine injections and the espresso. But the straight-up caffeine had a much smaller effect on blood pressure than the espresso, boosting systolic blood pressure by an average of just 6 mm Hg. Moreover, the coffee drinkers and the nondrinkers responded similarly to intravenous caffeine.”
But there was an anomaly. Harvard says there are hundreds of substances in coffee, and caffeine is usually the one named as raising blood pressure.
Their conclusions: Coffee raises blood pressure in people who don't drink it regularly. Younger people also are more sensitive to coffee's blood-pressure effects.
This seems to be on the same page with an interesting study cited by Verywellhealth.com, which showed: 
“... that the caffeine-blood pressure relationship may be more complicated than expected. The study examined how the amount of coffee consumed affected the risk of developing high blood pressure. While the results showed that the risk of high blood pressure was the lowest for those who drink no coffee, it also showed that those who drink a lot of coffee have almost the same risk. In an unexpected twist, people who drank only small amounts of coffee (1-3 cups per day) seemed to have the highest risk. It is believed that over time, the body becomes tolerant to the stimulant effects of caffeine.”
To test whether caffeine has an effect in raising your blood pressure, check your blood pressure between 30 and 120 minutes after ingesting caffeine. An increase of five to 10 points indicates you are sensitive to caffeine, and you should cut back on it, Mayo Clinic says. To avoid withdrawal symptoms such as headaches, irritability and fatigue, cut back over several days.
A doctor can tell you whether to stop taking caffeine or limit your intake of it if you do have high blood pressure. He may advise you to cut back and have no more than 200 milligrams of caffeine per day.
That equates to about two 12-ounce (355 ml) cups of coffee or five Viter Energy Mints. While the amount of caffeine varies a lot in coffee, Viter Energy Mints contains 40 milligrams of caffeine.
If you lift weights or do physical labor and have high blood pressure, avoid caffeine before engaging in those activities, Mayo Clinic says.
So while it appears there is little risk for high blood pressure among regular coffee drinkers, the question occurs: Are there other risk factors for health in consuming coffee and/or caffeine?
Coffee can cause:
And for those who consume a lot of caffeine, it may cause dizziness or headaches and excessive urination and dehydration.
But the benefits of coffee and possibly caffeine alone, ranging from mental to physical, are so many that experts advise people not to stop taking it but rather to take it in moderation - no more than 400 mg per day.
Here's more information on how much caffeine you should have in a day.
As many philosophers and doctors have said down through the centuries, all things in moderation. Don't overdo it, and you should be OK.
Dr Joe explains more information about the relationship between coffee and high blood pressure for the general population and for those with high blood pressure:
Stories of coming back from a downfall after great success are inspiring for anyone—even for young people who haven’t made their mark on the world yet. History and mythology are filled with people who were at the height of success, crashed and came back again.
Sometimes, people need to lose everything material to realize that they didn’t need it, or that the health and safety of their families are worth more than all the success and gold in the world. Sometimes people come back even stronger and more successful than before they “fell.”
Unless you work outdoors or indoors in a job where you are physically active all day, it can be difficult for some people who have desk jobs to stay awake at work without caffeine.
Maybe the most important thing you can do to make sure you don’t nod off at work is to get a good night of sleep, at least 7 to 8 hours, at a regular time every night. Boredom can also cause you to nod off. Other than getting a good night’s sleep and having a fascinating job, there are things you can do to stay awake.
How do investment bankers stay awake on their 18-hour shifts?
Investment bankers work such long hours that many resort to chemical stimuli. There have been rumors of methamphetamine and cocaine use among investment bankers to burn the midnight oil. Other investment bankers take Ritalin or Adderall, which are given to children with ADHD but which are stimulants for adults. But the mainstay is probably coffee, energy drinks, and other concoctions containing caffeine.