Heart rate 150 on an adult - what does it mean?
A resting heart rate of 150 bpm is clearly too high for an adult at rest. After exercise it can be normal; at true rest it needs medical attention if it does not settle within a few minutes.
Where 150 bpm sits on the adult scale
- Very low
- Low (bradycardia)
- Slightly low
- Normal
- Elevated (tachycardia)
- High
- Very high
What a resting pulse of 150 means
If you just climbed stairs, exercised or are very anxious, a pulse of 150 can be a normal response and should fall within minutes. A fast rate that persists at rest can come from fever, dehydration, blood loss or anemia, an overactive thyroid, or a heart rhythm disorder such as atrial fibrillation, atrial flutter or supraventricular tachycardia (SVT).
An irregular pulse at this speed is a typical sign of atrial fibrillation, which raises stroke risk and should always be evaluated.
Ranges apply to adults and children aged 10 and older, measured at rest (American Heart Association). By the numbers: at 150 bpm the heart beats about every 0.40 seconds — roughly 216,000 beats a day.
A pulse locked at 150: the atrial flutter clue
Doctors pay special attention to a resting rate that sits steadily at about 150 and barely moves. One classic cause is atrial flutter. In this rhythm, an electrical signal races in a loop around the right upper chamber of the heart, usually about 300 times a minute. The junction between the upper and lower chambers cannot pass all of those signals. Very often it lets every second one through, called 2:1 conduction, and 300 divided by 2 is 150.
That is why the number itself is a hint. Sinus tachycardia from fever or stress drifts up and down with breathing, movement and position. A flutter rate at 2:1 stays almost fixed, minute after minute, at or very near 150. On a watch graph it looks like a flat line. Sometimes the junction lets only every third or fourth signal through, giving a pulse of around 100 or 75 that can hide the problem, or the ratio changes from moment to moment and the pulse feels irregular.
What an ECG shows and why it matters
On an ECG, typical flutter shows a pattern of regular sawtooth waves between the normal beats, best seen in certain leads. The rhythm can be confused with other fast rhythms at first glance, which is why the ECG often has to be read carefully or repeated after a medicine briefly slows the heart.
Atrial flutter carries risks similar to atrial fibrillation, and many people have both. Blood can pool in the upper chambers, so there is a risk of clots and stroke. A heart that runs at 150 for days or weeks can also become weak and tired.
Treatment and what to do now
Care usually covers the same three areas as atrial fibrillation: preventing stroke, often with a blood thinner based on your risk factors; controlling the rate with medicines; and restoring a normal rhythm. A planned electric reset called cardioversion works well for many. Catheter ablation, which creates a small line of scar tissue to block the loop, is highly effective for the common type of flutter and often a long-term fix.
If your pulse sits at a steady 150 while you rest, this page’s rule applies firmly: after ten to fifteen minutes of rest at a rate still above 120, contact a doctor today, and the emergency department is the right place if you cannot be seen quickly, because a steady fast rhythm may need treatment through a drip or a controlled shock. Call 911 for chest pain, fainting, severe breathlessness, confusion or any stroke sign such as a drooping face, arm weakness or slurred speech. Our heart rate monitors page explains which devices can capture the rhythm for your doctor.
150 bpm during exercise
During exercise a higher pulse is expected. This table shows which training zone 150 bpm corresponds to, based on the common estimate of maximum heart rate (220 minus age). Individual maximums can differ by 10–20 bpm.
| Age | Est. max (220 − age) | 150 bpm is | Training zone |
|---|---|---|---|
| 20 | 200 bpm | 75% of max | Zone 3 · Moderate |
| 30 | 190 bpm | 79% of max | Zone 3 · Moderate |
| 40 | 180 bpm | 83% of max | Zone 4 · Hard |
| 50 | 170 bpm | 88% of max | Zone 4 · Hard |
| 60 | 160 bpm | 94% of max | Zone 5 · Maximum |
| 70 | 150 bpm | 100% of max | Zone 5 · Maximum |
How the zones work: Heart Rate Zones: The 5 Training Zones by Age.
For a reliable resting value, sit quietly for five minutes first and average a few mornings: Resting Heart Rate: What It Says About Your Health. You can also measure by tapping along on the start page.
Check another reading
Nearby values
Measured on a child instead? See heart rate 150 in a child.
Sources: American Heart Association: All About Heart Rate · MedlinePlus: Pulse · ACSM position stand on exercise intensity (2011)
This page explains a single reading in general terms. It is not a diagnosis. Heart rate alone cannot tell whether the rhythm is regular or whether the heart is healthy — if you are worried, talk to a doctor.