Heart rate 37 on an adult - what does it mean?

Where 37 bpm sits on the adult scale

What a resting pulse of 37 means

Very slow resting rates in people who are not highly trained can mean the heart's electrical system is not keeping pace — for example sinus node dysfunction or a heart block — or can be a medication effect (beta blockers, some calcium channel blockers, digoxin). An underactive thyroid, low body temperature and electrolyte problems are other causes.

Rule out a measuring error first: a weak or irregular pulse is easy to undercount by hand, and some wrist wearables miss beats. Count for a full 60 seconds at the wrist or use a chest-strap or blood-pressure monitor.

Ranges apply to adults and children aged 10 and older, measured at rest (American Heart Association). By the numbers: at 37 bpm the heart beats about every 1.62 seconds — roughly 53,280 beats a day.

A resting 37 and the pacemaker question

People who see a reading in the high 30s often wonder whether they will need a pacemaker. The honest answer is that the number alone does not decide it. Cardiologists base the decision on two things together: what the ECG or a longer recording shows, and whether the slow rhythm causes symptoms.

A fit cyclist who rests at 37, climbs to high rates on a hill and feels great is a different case from a 78-year-old who sits at 37, gets breathless walking to the mailbox and has had dizzy spells. The first usually needs no device. The second very likely does, once reversible causes are ruled out.

Doctors may also use a treadmill test to see whether the rate rises with effort, and a recorder worn for days to catch pauses that a short tracing misses.

Situations where a device is usually recommended

• a slow rhythm that clearly matches symptoms such as fainting, near-fainting, marked fatigue or breathlessness
• complete heart block, or the type of second-degree block (Mobitz II) that tends to progress, often even without symptoms
• sick sinus syndrome with symptoms, including the pattern where fast spells end in long pauses
• a slow rate caused by a medicine that the person truly needs and cannot do without

Before deciding, doctors look for causes that can be fixed: an underactive thyroid, high potassium, Lyme disease, too much of a rate-lowering drug, or sleep apnea.

What the procedure and life afterwards involve

A standard pacemaker is a small metal box placed under the skin below the collarbone, usually under local anaesthetic with sedation. One or two thin wires run through a vein into the heart. Some newer leadless models are placed inside the heart through a vein in the leg. Many people go home the same day or the next.

The device watches every beat and only fires when the natural rate drops below a programmed minimum. Arm movement on that side is limited for a few weeks while the wires settle. After that most people return to normal activity, including exercise and travel. Regular checks, often partly done remotely, track the battery, which typically lasts many years.

Keep phones and magnets a short distance from the device, and show your device card at airport security. Until a plan is in place, see a doctor promptly about a resting 37, and call 911 for fainting or chest pain.

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.

Nearby values

• 32 bpm
• 33 bpm
• 34 bpm
• 35 bpm
• 36 bpm
• 38 bpm
• 39 bpm
• 40 bpm
• 41 bpm
• 42 bpm

Measured on a child instead? See heart rate 37 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.