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High resting heart rate: causes and how to lower it
Key takeaways
- A normal adult resting heart rate is 60–100 bpm; above 100 is tachycardia.
- Even within the normal range, a resting rate that has drifted up from your usual baseline is worth noticing.
- Common causes: stress, poor sleep, dehydration, caffeine, alcohol, illness and low fitness.
- Regular aerobic exercise, sleep and hydration can lower resting heart rate over weeks.
What is a high resting heart rate?
Your resting heart rate is your pulse when you are calm, sitting or lying down, and not recently active. For adults, 60–100 bpm is normal; athletes often sit in the 40s or 50s. A resting heart rate consistently above 100 bpm is called tachycardia. Large studies link resting rates in the upper part of the normal range with higher cardiovascular risk, so knowing your own baseline matters. Check resting heart rate by age for typical values.
12 common reasons your heart rate is high
- Stress or anxiety — adrenaline speeds the heart.
- Poor or short sleep.
- Dehydration — less blood volume means more beats.
- Caffeine and energy drinks.
- Alcohol, especially the night before.
- Nicotine and vaping.
- Illness or fever — roughly 10 bpm higher per 1 °C (see flu symptoms).
- Heat and humidity.
- Low fitness or recent weight gain.
- Medicines such as decongestants, inhalers, thyroid medicine and ADHD stimulants.
- Anemia or an overactive thyroid.
- Pregnancy — resting rate rises by about 10–20 bpm.
How to lower your resting heart rate
- Move regularly: 150 minutes a week of moderate activity, such as brisk walking, gradually lowers resting rate.
- Sleep 7–9 hours on a regular schedule.
- Drink enough water, especially in heat or illness.
- Cut back on caffeine and alcohol, and stop smoking.
- Practice slow breathing: about six breaths a minute for a few minutes calms the nervous system and can lower your pulse in the moment.
- Manage stress — and check in on your mood; anxiety is a frequent hidden cause.
When to see a doctor
- Your resting rate is regularly above 100 bpm without a clear reason.
- It rises well above your usual baseline and stays there.
- You have palpitations, dizziness, fainting, chest discomfort or shortness of breath — call 911 for chest pain or fainting.
- Episodes start and stop suddenly.
How to measure it properly
Measure in the morning, before coffee, after sitting quietly for a few minutes, in the same position each day. Compare weekly averages rather than single readings.
Cardivo reads your heart rate and HRV with your fingertip on the iPhone camera in about 30 seconds and shows your resting pulse against people your age, plus a "Resting heart-rate check-in" plan and stress and energy scores. It also syncs Apple Watch data through Apple Health. Learn more in how to measure heart rate without an Apple Watch.
This guide is general wellness education based on the public sources below. It is not medical advice, diagnosis, or treatment. Cardivo is not a medical device. If you think you are having a medical emergency, call 911.
Frequently asked questions
What is a dangerously high resting heart rate?
A resting heart rate above 100 bpm is tachycardia and worth discussing with a doctor. A fast rate with chest pain, fainting or severe shortness of breath is an emergency.
Why is my heart rate high when I'm resting?
Common reasons include stress, poor sleep, dehydration, caffeine, alcohol, illness or fever, heat, some medicines, anemia and an overactive thyroid.
How can I lower my resting heart rate fast?
In the moment, slow breathing (about six breaths per minute), drinking water and resting in a cool place help. Over weeks, regular aerobic exercise and better sleep lower it most.
Sources
- American Heart Association — Target heart rates
- American Heart Association — Tachycardia
- Harvard Health — How's your heart rate and why it matters