Heart rate 109 on an adult - what does it mean?

Where 109 bpm sits on the adult scale

What a resting pulse of 109 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 109 bpm the heart beats about every 0.55 seconds — roughly 156,960 beats a day.

Thyroid overdrive behind a resting 109

The thyroid gland in the front of the neck sets the pace of the body’s metabolism. When it produces too much hormone, a condition called hyperthyroidism, almost every system speeds up, and the heart is one of the first places it shows. A resting pulse that sits above 100, day and night, without fever, exercise or caffeine to explain it, is one of the classic reasons doctors order a thyroid test.

Several conditions can cause it:

• Graves disease, an autoimmune condition and the most common cause in the US, sometimes with bulging or irritated eyes.
• Overactive nodules, lumps in the thyroid that make hormone on their own.
• Thyroiditis, inflammation that releases stored hormone for a time, for example in the months after pregnancy.
• Too high a dose of thyroid hormone tablets in someone being treated for an underactive thyroid.

The rest of the picture

A fast heart rarely comes alone. People often notice weight loss despite a good or bigger appetite, feeling hot and sweaty when others are comfortable, trembling hands, nervousness or irritability, trouble sleeping, more frequent bowel movements, thinning hair, muscle weakness in the thighs and lighter or irregular periods. Older adults may have fewer of these and mainly feel tired, low or breathless.

An overactive thyroid also makes the heart’s upper chambers more irritable. It is a known trigger of atrial fibrillation, especially in people over 60, which is why a new irregular rhythm is usually followed by a thyroid check.

Testing and treatment

The first test is a blood level of TSH, the hormone the pituitary gland uses to control the thyroid. In hyperthyroidism TSH is usually low, and the thyroid hormones themselves are high. Further tests, such as antibodies or a thyroid scan, show which cause is at work.

Doctors often prescribe a beta blocker at first to slow the heart and ease the shaking while the main treatment takes effect. That main treatment may be anti-thyroid medicine, radioactive iodine or, less often, surgery. As hormone levels return to normal, the resting rate usually falls back into the normal range. If you take thyroid hormone and your pulse has crept up, do not change the dose yourself; ask for a blood test. Read about other ways to bring a high rate down on how to lower your heart rate.

Very high fever, confusion, vomiting and a racing heart in someone with known thyroid disease can signal a rare crisis that needs emergency care.

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

• 104 bpm
• 105 bpm
• 106 bpm
• 107 bpm
• 108 bpm
• 110 bpm
• 111 bpm
• 112 bpm
• 113 bpm
• 114 bpm

Measured on a child instead? See heart rate 109 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.