Sinus bradycardia, or a slow heart rate, can be a sign of cardiovascular health in young, healthy adults and endurance athletes. But it can also be a sign of an underlying condition requiring medical attention.

Bradycardia happens when your heart rate is slower than typical. Your heart normally beats between 60 and 100 times per minute. Bradycardia is defined as a heart rate slower than 60 beats per minute.

Though it’s most common in older adults, it can affect anyone and may occur alongside other conditions, including sinus arrhythmia.

But what causes sinus bradycardia? And is it serious? Continue reading as we explore more about sinus bradycardia as well as how it’s diagnosed and treated.

Why is it called sinus bradycardia?

Sinus bradycardia is a type of slowed heart rate that originates from the sinus node of your heart.

Some people refer to the sinus node as the heart’s pacemaker. It generates the organized electrical impulses that cause your heart to beat.

Meanwhile, the term “bradycardia” is used to describe a heart rate that’s slower than typical.

Sinus bradycardia doesn’t always indicate a health problem. In some people, the heart can still pump blood efficiently with fewer beats per minute. For example, healthy young adults or endurance athletes can have sinus bradycardia.

It can also occur during sleep, particularly when you’re in a deep sleep. Though it can happen to anyone, it’s more common in older adults.

Sinus bradycardia can also occur along with sinus arrhythmia. Sinus arrhythmia happens when the timing between sinus heartbeats is irregular. For example, in someone with sinus arrhythmia, the timing between heartbeats may vary when they inhale and exhale.

Both sinus bradycardia and sinus arrhythmia may commonly occur during sleep. Sinus bradycardia can be a sign of a healthy heart. But it can also be a sign of a failing electrical system. For example, older adults may develop a sinus node that doesn’t work to generate electrical impulses reliably or fast enough.

Sinus bradycardia can cause problems if the heart isn’t efficiently pumping blood to the rest of the body. Some possible complications from this include:

Many people who have sinus bradycardia don’t have any symptoms aside from a slower heart rate.

But if not enough blood is being pumped to the organs of your body, you may begin to experience symptoms, including:

Sinus bradycardia happens when your sinus node generates a heartbeat fewer than 60 times in a minute. Many possible factors can cause this to occur. Potential causes of sinus bradycardia can include:

Because bradycardia can be caused by damage to the heart, factors associated with heart disease may also be linked to a higher risk of sinus bradycardia. Risk factors for heart disease may include:

To diagnose sinus bradycardia, a doctor typically first conducts a physical exam. This can include things like:

They may also take your medical history. They may ask you about your symptoms, what medications you’re currently taking, and if you have any underlying health conditions.

A doctor uses an electrocardiogram (ECG) to detect and characterize bradycardia. This test measures the electrical signals that pass through your heart using several small sensors attached to your chest. It delivers results as a wave pattern.

Bradycardia may not occur while you’re in the doctor’s office. Because of this, a doctor may ask you to wear a portable ECG device or “arrhythmia monitor” to record your heart’s activity. You may need to wear the device for a few days or sometimes longer.

A few other tests may be performed as part of the diagnostic process. These can include:

  • Stress testing: A stress test monitors your heart rate while you exercise. This can help a doctor understand how your heart rate responds to physical activity.
  • Blood tests: These tests can help detect whether things like an electrolyte imbalance, an infection, or a condition like hypothyroidism may be causing your condition.
  • Sleep monitoring: Sleep monitoring can be used to detect sleep apnea that may be causing bradycardia, especially at night.
  • Toxicology screening: A toxicology screen checks for drugs or other chemicals in your blood that could contribute to sinus bradycardia.
  • Cardiac troponin testing: A cardiac troponin test is used to determine blood levels of troponin, a type of protein found in the heart muscles that indicates damage to the heart.
  • Transthoracic echocardiography: A transthoracic ECG allows doctors to look at the heart’s anatomy and function.

Other tests may also be used to diagnose sinus bradycardia, including a chest X-rays, urinalysis, or viral panels.

A doctor can help determine which tests may be beneficial for diagnosing the cause of your symptoms and deciding whether or not treatment is necessary.

You may not require treatment if you have sinus bradycardia but it isn’t causing symptoms.

For those who experience symptoms or otherwise need treatment, how the condition is treated depends on what’s causing it. Some treatment options may include:

  • Treating underlying conditions: If something like thyroid disease, sleep apnea, or an infection is causing sinus bradycardia, a doctor can help develop a treatment plan to address it.
  • Adjusting medications: If a medication you’re taking is causing your heart rate to slow, a doctor may either adjust the dosage of the medication or withdraw it completely, if possible.
  • Implanting a pacemaker: People with frequent or severe sinus bradycardia may need a pacemaker. This is a small device that’s implanted in your chest. It uses electrical impulses to help maintain a regular heart rate.

A doctor may also suggest making certain lifestyle changes. These can include things like:

In most cases, you should start to feel better shortly after starting treatment for sinus bradycardia or addressing the underlying conditions that may cause it.

Recovery may take several weeks if you require a pacemaker to manage frequent or severe sinus bradycardia. During this time, it’s important to avoid heavy lifting, placing pressure on the area where your pacemaker is implanted, or wearing clothing that rubs on the incision.

A healthcare professional can provide more in-depth information about your treatment plan, including when you should expect to feel better. It may depend on:

  • the cause
  • the severity of your symptoms
  • your overall health

While it’s not usually possible to prevent sinus bradycardia, you can take certain steps can help reduce your risk, prevent complications, and help keep your heart healthy.

These may include:

  • avoiding smoking or vaping, if applicable
  • getting regular physical activity
  • reaching or maintaining a moderate weight
  • following a heart-healthy diet, which includes plenty of fruits, vegetables, whole grains, and minimally processed foods
  • working with a healthcare professional to manage high blood pressure or high cholesterol levels

Many people with sinus bradycardia don’t experience any symptoms and may not require treatment.

For individuals who do experience symptoms, early diagnosis and treatment from a healthcare professional can significantly improve the outcome of this condition.

Making changes to your diet and lifestyle and working with a doctor to manage other underlying conditions can also prevent heart damage and minimize complications.

The following includes frequently asked questions about sinus bradycardia.

What can I expect if I have this condition?

Many people with sinus bradycardia may not experience symptoms and may not require treatment. If you notice symptoms, it’s best to consult with a doctor to determine the cause and begin treatment. This can help prevent complications and improve your outlook.

How long does bradycardia last?

Sinus bradycardia can be a short-term issue that’s resolved quickly, especially if it’s caused by certain medications, electrolyte imbalances, or acute infections. However, if it’s caused by a congenital or chronic health condition, it might require a permanent pacemaker to help manage symptoms.

How do I take care of myself?

If you’ve received a diagnosis of sinus bradycardia, taking medications as prescribed and having regular checkups with a doctor to address any concerns can help you recover. A doctor may also recommend following a heart-healthy, well-rounded diet, staying active, and managing other underlying conditions.

If you’re experiencing symptoms consistent with sinus bradycardia, you may want to make an appointment with a doctor. While sometimes sinus bradycardia doesn’t need treatment, other times it can signal serious health conditions that need attention.

The Healthline FindCare tool can provide options in your area if you don’t already have a doctor.

When it’s an emergency

Always contact 911 or local emergency services if you experience:

  • chest pain that lasts longer than a few minutes
  • trouble breathing
  • fainting

Sinus bradycardia is a slow, regular heart rate. It happens when your heart’s pacemaker, the sinus node, generates a heartbeat fewer than 60 times in a minute.

For some people, such as healthy young adults and athletes, sinus bradycardia can be a sign of cardiovascular health.

It can also occur during deep sleep. Many people with the condition don’t even know they have it.

Sometimes, sinus bradycardia can cause symptoms, including dizziness, fatigue, and fainting. If you experience these symptoms, see a doctor.

They can work with you to diagnose sinus bradycardia and develop a treatment plan, if needed.