Your heart rate is supposed to change throughout the day.
It might climb when you’re rushing around and drop when you’re resting. It might even look a little different from one day to the next.
But now that smartwatches, fitness trackers and health apps put those heart rate changes right in front of us, it’s easy to start wondering what they actually mean.
“One of the most common questions I hear is whether a particular heart rate is dangerous,” says Sarfaraz Memon, MD, a cardiologist with Hartford HealthCare’s Heart & Vascular Institute. “The reality is that your heart rate is only one piece of the puzzle. We always look at the bigger picture, including symptoms, medical history and what you were doing when that heart rate occurred.”
Luckily, most heart rate changes aren’t emergencies. But there are times when your pulse deserves a closer look.
1. First, get a baseline
Most adults have a resting heart rate between 60 and 100 beats per minute. But that’s a guideline, not a rule.
Some people naturally run lower. Others naturally run higher.
A marathon runner may sit comfortably in the 50s, while someone else may regularly be in the 80s and be perfectly healthy.
“Don’t get too caught up in the number itself,” Dr. Memon urges. “We’re equally interested in trends. If your resting heart rate has been 65 for years and suddenly it’s consistently 90, that’s more meaningful than an isolated reading.”
That’s why it’s helpful to know what your baseline is.
“What matters is understanding what’s typical for your body,” Dr. Memon adds. “A number outside the average range doesn’t automatically mean something is wrong, just as a number inside the range doesn’t automatically mean everything is fine.”
> Related: How Alcohol Affects Your Heart: 6 Risks You Should Know
2. A high heart rate isn’t always bad news
Your heart rate is supposed to go up throughout the day.
Exercise, stress, excitement, caffeine, dehydration, poor sleep and even running late to work can all send your pulse climbing. In many cases, that’s exactly what a healthy heart should do.
“A higher heart rate is a normal response to increased demand,” says Dr. Memon. “If you’re exercising, dealing with stress or fighting an illness, your heart may have to work harder temporarily.”
The question is what happens when you’re doing absolutely nothing.
“If you’re sitting quietly and your heart is still racing, that’s something we want to understand,” Dr. Memon says. “It may be harmless, but it can also signal an arrhythmia or another medical condition that needs a closer look.”
> Related: 6 Signs Your Heart Might Be Struggling
3. A low heart rate can be completely normal, too
Seeing a number below 60 can be alarming if you don’t know what you’re looking at.
But for many healthy adults, especially those who exercise regularly, a slower resting heart rate can simply mean the heart is working efficiently.
“If you’re active, a lower resting heart rate is often a sign that your heart has become stronger and better at pumping blood,” says Dr. Memon. “Your heart doesn’t need to beat as frequently to meet your body’s needs.”
The bigger concern isn’t the number. It’s how you feel.
“If a slower heart rate is accompanied by dizziness, fainting, unusual fatigue, confusion or shortness of breath, that’s a different conversation,” Dr. Memon adds. “Those symptoms suggest your body may not be getting enough blood flow.”
Want a Weekly Dose of Health News?
4. Symptoms matter more than the number on your watch
A heart rate of 110 isn’t automatically dangerous. A heart rate of 55 isn’t automatically reassuring. The number only tells part of the story.
“We always ask patients how they feel,” says Dr. Memon. “Heart rate becomes much more significant when it’s associated with symptoms.”
Pay attention if heart rate changes come with:
- Chest discomfort
- Shortness of breath
- Dizziness
- Lightheadedness
- Fainting
- Unusual fatigue
- Heart pounding or fluttering
And don’t ignore those symptoms simply because your watch says your heart rate is normal.
“A person can have a serious heart rhythm issue and still have heart rates that appear relatively normal,” Dr. Memon says.
> Related: Your Blood Pressure May Be Rising While You Sleep. Here’s Why
5. Don’t ignore a heart that feels like it’s flip-flopping
Many people describe the sensation as fluttering, skipping, pounding or feeling like their heart briefly somersaulted in their chest.
“It’s difficult to describe, but it feels unsettling,” says Dr. Memon.
The occasional skipped beat is common and often harmless. But frequent episodes deserve attention.
“If these sensations are new, happening more often or occurring alongside symptoms like dizziness or shortness of breath, it’s worth getting evaluated,” Dr. Memon adds.
“That’s particularly true if they interfere with daily life.”
> Related: What Your Heart Rate Says About Your Health
When to see a doctor
Heart rate numbers can be helpful, but they don’t tell the whole story on their own.
A temporary increase after exercise, stress or a strong cup of coffee is usually expected. But persistent changes, irregular rhythms or symptoms like chest pain, fainting or shortness of breath deserve medical attention.
“Heart rate is one of many clues we use to understand cardiovascular health,” says Dr. Memon. “When something feels unusual for you, it’s worth having a conversation rather than trying to figure it out alone.”
