Heart rate 108 on an adult - what does it mean?

Where 108 bpm sits on the adult scale

What a resting pulse of 108 means

Common temporary causes: caffeine or energy drinks, nicotine, alcohol (also the day after), stress or anxiety, fever or infection, dehydration, a large meal, heat, pain, and recent physical activity. Decongestants, asthma inhalers and thyroid medication can also raise the pulse.

Sit quietly for five minutes and measure again. If your resting pulse is repeatedly above 100, causes worth checking include anemia, an overactive thyroid, heart rhythm disorders such as atrial fibrillation, and low fitness after illness.

Ranges apply to adults and children aged 10 and older, measured at rest (American Heart Association). By the numbers: at 108 bpm the heart beats about every 0.56 seconds — roughly 155,520 beats a day.

When thin blood drives the rate to 108

Red blood cells carry oxygen from the lungs to the rest of the body using a protein called hemoglobin. In anemia there is less hemoglobin than normal, so each heartbeat delivers less oxygen. The heart compensates the only way it can: by pumping more often. A mild anemia may add only a few beats. A more marked one can hold a resting pulse above 100, and climbing stairs may send it much higher.

Anemia is not one condition but a result with several possible causes:

• Blood loss, slow or sudden: heavy periods, bleeding from the stomach or bowel, frequent blood donation.
• Too few building blocks: iron, vitamin B12 or folate.
• Long-term illness, such as kidney disease or inflammatory conditions, which slows red cell production.
• Inherited conditions that affect hemoglobin or red cell survival.

How anemia tends to feel

Because it usually develops over weeks or months, many people get used to it. Common signs are tiredness that sleep does not fix, getting out of breath on stairs or hills, pale skin or pale inner eyelids, cold hands and feet, headaches and a pounding heartbeat on exertion. Some people notice a craving to chew ice.

A simple blood test, the complete blood count, shows the hemoglobin level. Doctors then add tests to find the cause, such as ferritin for iron stores or a B12 level. Finding the cause matters as much as fixing the number, especially when blood loss from the gut is possible. Taking iron pills on your own without testing can hide that kind of bleeding and is not a good substitute for a check-up.

What happens to the pulse during treatment

Once the cause is treated and red cells are rebuilt, the resting rate usually falls. With iron or vitamin replacement this takes weeks rather than days, because new blood cells need time to form. Tracking your morning pulse during treatment is an easy way to see progress alongside repeat blood tests. Our resting heart rate guide shows how to measure that baseline consistently.

Sudden blood loss is different. A fast pulse with black, tarry stools, vomiting blood or material that looks like coffee grounds, very heavy bleeding, or feeling faint and clammy is an emergency. Call 911 or go to the emergency room.

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

• 103 bpm
• 104 bpm
• 105 bpm
• 106 bpm
• 107 bpm
• 109 bpm
• 110 bpm
• 111 bpm
• 112 bpm
• 113 bpm

Measured on a child instead? See heart rate 108 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.