You probably don’t check your heart rate except during your workouts. It's reasonable to see the number tick up as you put your body through the paces, but it can be a little jarring when the beats are coming faster on your tracker even though you're sitting still or your heart rate won't go down after resting post-activity.
Let’s back up a sec here: Your heart beat is the result of a special electrical system, says Gioia Turitto, MD, a cardiologist at NewYork-Presbyterian Brooklyn Methodist Hospital. “With each cycle, an electrical signal is generated by the system operator—the sinus node—and sent through a complex grid from the top to the bottom of the heart,” she explains. “As this happens, the electrical stimulus is converted into a mechanical response; the resulting heart contraction pumps blood out to rest of the body.”
For the record, cardiologists say it’s completely normal for your heart rate to jump up sometimes. “When the body is exercising or under various stressors, the heart responds with an increased rate to match the circulatory needs of your body,” notes Laura Franey, MD, a Corewell Health cardiologist.
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For example, when you're exercising, your musculoskeletal system requires more oxygenated blood to perform. The heart meets this need by raising your heart rate. Most of the time, an elevated heart rate is a response to a physical demand rather than an indication of a heart problem, Dr. Franey says.
Meet the experts: Gioia Turitto, MD, is a cardiologist at NewYork-Presbyterian Brooklyn Methodist Hospital. Laura Franey, MD, is a Corewell Health cardiologist. Ronald Maag, MD, is the medical director of the Baylor Heart Clinic and an assistant professor of medicine-cardiology at Baylor College of Medicine.
Still, if your heart rate is staying at that elevated level, you may have some questions. There are definitely certain situations where you’ll want to get checked out—this is your heart, after all.
What’s considered a normal heart rate?
A normal heart beat range when you’re at rest is 60 to 100 beats per minute, according to the American Heart Association (AHA). “I liken it to a thermostat,” says cardiologist Ronald Maag, MD, the medical director of the Baylor Heart Clinic and an assistant professor of medicine-cardiology at Baylor College of Medicine. “Everyone’s is different and anything in that range is normal.”
Exercise, pain, stress, and anxiety can make your heart rate jump up, Dr. Maag says. For the record, it’s normal for your heart rate to jump above 100 when you do vigorous exercise (the AHA has a handy chart that details target heart rate zones during exercise, if you’re curious). However, having a heart rate over 100 beats per minute when you’re at rest is a condition known as tachycardia.
So, how do you know when your heart rate is an issue? “The main clue is how aware of it you are and what other symptoms go along with it,” says Sarina van der Zee, MD, a cardiac electrophysiologist and cardiologist at Providence Saint John’s Health Center in Santa Monica.
If it feels fast to you when you’re at rest or suddenly jumps up and back down, that can be a clue that there’s a problem. Other symptoms like chest pain, trouble breathing, dizziness, and lightheadedness with your fast heart beat can also indicate that something is off, she adds.
Overall, though, “there isn’t necessarily a magic number that’s considered too high because the heart rate itself doesn’t tell the whole story,” says Jim Liu, MD, a cardiologist at The Ohio State University Wexner Medical Center.
10 Common Causes of a Fast Heart Rate
There are a few things that can cause your heart rate to jump up outside of exercise and stress, and some are more serious than others. Keep these in mind if you’re concerned about your own heartbeat.
1. You have a fever.
Being sick with a fever can cause your heart rate to become elevated, according to the Mayo Clinic. In this situation, you’d likely have other symptoms, including chills, Dr. Maag says. Once your fever goes down—taking acetaminophen or another fever-reducing medication may help—your heart rate should too.
2. You drank too much.
Heavy alcohol use can cause your heart rate to go up, along with going through alcohol withdrawal. Keep this in mind too: If you tend to drink a lot on a regular basis, your heart rate can go up and stay up. That doesn't mean you have to cut it out completely—just cap it at one drink per day to minimize any potential harmful effects of indulging too much, according to the CDC.
3. You had too much caffeine.
Caffeine is a stimulant and that can make your heart rate jump up, Dr. Franey says. Just how much is too much, though? That's 400 milligrams of caffeine a day, which translates to four to five cups of coffee, per the FDA.
That said, everyone reacts differently to caffeine. Whether you've consumed more than your body can take really comes down to how you feel. If you find yourself suffering from insomnia, jitters, anxiousness, and yep, a fast heart rate, it's time to consider cutting back or switching to a less caffeinated option for an energy boost, like green tea or matcha.
4. You have high—or low—blood pressure.
Bizarrely, both ends of the blood pressure spectrum can cause an increase in your heart rate. You may assume your heart rate and blood pressure increase at the same rate, but that's not necessarily the case. When your heart pumps out more beats per minute, your blood vessels dilate to let allow more blood flow through more easily. So, even when you see a big jump in your heart rate, the increase in your blood pressure may only be moderate. However, research has linked a fast heart rate to a higher risk of high blood pressure.
On the other hand, you might have a temporary increase in your heart rate when you have low blood pressure if you stand up, per the Cleveland Clinic, but it should just be a short-term issue.
This is a talk-to-your-doctor kind of thing: They can help determine what’s affecting your blood pressure and take things from there.
5. You have an electrolyte imbalance.
Electrolytes like potassium, sodium, calcium, and magnesium can all interfere with your heart rate, Dr. van der Zee says. An imbalance (either too much or too little) can mess with your heart signaling and cause irregular heartbeats, according to the Mayo Clinic.
If you suspect you’re regularly dealing with an electrolyte imbalance, it’s a good idea to talk to your doctor.
6. You have side effects from a medication.
A slew of medications can cause your heart rate to increase, Dr. Franey says, including decongestants, thyroid medications, and some drugs for anxiety and depression. If you think that your new medication is messing with your heart, talk to your doctor and ask about the possibility of swapping out your meds.
7. You have an overactive thyroid.
An irregular or fast heartbeat is a symptom of hyperthyroidism, which is when your thyroid gland makes too much thyroid hormone, according to the Mayo Clinic. Other telltale signs include unintentional weight loss, heart palpitations, tremors, increased appetite, and sweating and increased sensitivity to heat.
This disease is common in women and those who have a family history of thyroid disease or were recently pregnant, according to the National Library of Medicine. There are many different causes of hyperthyroidism, but if you're showing signs, you'll need to see a doctor. They may prescribe medications or surgery to remove the organ.
8. You have anemia.
Anemia is a condition where you don’t have enough healthy red blood cells to carry enough oxygen to your body's tissues, according to the National Institutes of Health. When you're anemic, your heart pumps more blood to make up for the lack of oxygen in the blood, raising your heart rate in the process, the Mayo Clinic says. Your doctor will need to test you for anemia and can recommend a proper treatment from there.
9. You smoke.
Smoking can increase your resting heart rate, according to the AHA. If you smoke and are ready to quit, talk to your doctor about your options.
10. You used illegal drugs.
Illegal drugs—especially stimulants like cocaine or methamphetamine—are notorious for jacking up your heart rate. They essentially put more demand on your heart, causing it to be faster in the process, the AHA says.
When do you need to see a doctor about a fast heart rate?
If you have a fast heart rate and you’re concerned, that should be enough to flag it for your doctor. But it’s a good idea to contact your doctor sooner rather than later if you have a new, elevated heart rate that’s consistently over 100 beats per minute while you’re at rest, Dr. Franey says.
Symptoms like chest pain, shortness of breath, or severe lightheadedness along with a fast heart rate should cause you to seek help immediately, she says.