Heart rate 35 on an adult - what does it mean?

Where 35 bpm sits on the adult scale

What a resting pulse of 35 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 35 bpm the heart beats about every 1.71 seconds — roughly 50,400 beats a day.

Sick sinus syndrome: when the natural pacemaker falters

The sinus node is a small cluster of cells in the wall of the right atrium. It fires on its own and sets the pace for the whole heart. With age, scarring or other damage, it can become unreliable. Doctors call this sinus node dysfunction, and when it causes symptoms, sick sinus syndrome. A resting pulse in the mid-30s is one way it shows itself.

The condition is most common in older adults, but it can occur at any age, including after heart surgery. It usually develops slowly, so people may put early signs down to getting older. Family members sometimes notice first, for example that someone dozes off more, gets muddled at times or stops halfway up the stairs.

The patterns it can produce

• Persistent slow rate. The node fires too seldom, giving rates in the 30s or 40s even while awake.
• Pauses. The node stops for a few seconds before restarting. Long pauses can cause sudden dizziness or a blackout.
• Poor response to activity. The rate rises too little when you climb stairs, so you tire quickly and get breathless. Doctors call this chronotropic incompetence.
• Tachy-brady syndrome. Spells of a fast, often irregular rhythm such as atrial fibrillation alternate with slow stretches. The pause after a fast run ends can be the moment someone faints.

Because the problem comes and goes, a short ECG in the clinic may look normal. A recorder worn for one or more days, or a longer event monitor, often catches the slow periods and links them to symptoms.

Treatment and what you can do now

Sick sinus syndrome that causes symptoms is commonly treated with a pacemaker, which steps in whenever the natural rate falls too low. People with the fast-slow pattern may also need medicine to control the fast spells, which is safer once a pacemaker protects against slow ones. Doctors also review existing drugs, since beta blockers and some calcium channel blockers can make sinus node problems worse.

If you have a resting rate around 35, keep a diary of readings and symptoms with times, and see a doctor promptly. Note whether dizzy moments follow a racing feeling. Call 911 if you faint, have chest pain or struggle to breathe. Do not stop a prescribed heart medicine on your own. The normal adult heart rate page shows where typical waking values lie for comparison.

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

• 30 bpm
• 31 bpm
• 32 bpm
• 33 bpm
• 34 bpm
• 36 bpm
• 37 bpm
• 38 bpm
• 39 bpm
• 40 bpm

Measured on a child instead? See heart rate 35 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.