Your Guide to Holter Monitors

Medically Reviewed By Uzochukwu Ibe, MD, MPH
Was this helpful?

A Holter monitor is a painless test that records your heart’s electrical activity continuously, usually for 1–2 days. A Holter monitor is a longer version of an EKG (electrocardiogram). A Holter monitor is only one method clinicians use to monitor and diagnose heart conditions. Talk with your doctor about all the options for evaluating heart health to understand which ones are right for you.

Keep reading to learn more about the benefits of Holter monitors, their risks, and how you can prepare for one. This article also discusses what to expect during and after the procedure.

Why is a Holter monitor necessary?

Print Medical illustration by Maya Chastain

Your doctor may recommend a Holter monitor to evaluate your heart health. It provides important information about the functioning of your heart in relation to other factors.

A Holter monitor by itself cannot diagnose all types of heart conditions or predict future heart problems. It is used together with other information such as your age, medical history, physical exam, and other tests.

Your doctor may recommend a Holter monitor to diagnose cardiac arrhythmias, or irregular heartbeats. It can help them determine their severity and guide treatment. Holter monitors can indicate whether heartbeats are too fast, too slow, irregular, or infrequent.

A Holter monitor can also help determine if certain symptoms are related to a heart problem. These can include:

Learn more about the symptoms of heart conditions.

Who performs a Holter monitor test?

A nurse or technician will set up your Holter monitor. The following clinicians order and interpret Holter monitor testing:

  • Cardiologists: They specialize in diagnosing and treating diseases and conditions of the heart and its blood vessels.
  • Cardiac surgeons: They specialize in the surgical treatment of conditions of the heart and its blood vessels. Cardiac surgeons may also be known as cardiothoracic surgeons.
  • Electrophysiologists: These are cardiologists who specialize in treating heart rhythm disturbances, or arrhythmias.
  • Interventional cardiologists: These are cardiologists who specialize in diagnosing and treating heart disease using catheter procedures and radiological imaging.
  • Pediatric cardiologists: They specialize in diagnosing and treating diseases and conditions of the heart and its blood vessels in children.

Learn how doctors diagnose heart failure.

How is a Holter monitor test performed?

Your Holter monitor will be applied in a medical setting. Testing generally includes the following steps:

  1. Your provider will attach several sticky, painless patches, or electrodes, to your chest. They may shave small areas of your chest if needed.
  2. The electrodes are then connected to a Holter monitor device with wires. The monitor is about the size of a smartphone. You wear it clipped to a belt or in a pouch slung over the neck or shoulder.
  3. During your Holter monitor test, you will likely go about your normal activities. Sometimes, doctors may suggest limiting activities or provide specific instructions for activity level.
  4. You may need to press a button on the Holter monitor to record certain symptoms. These can include chest pain, dizziness, or a racing or pounding heart. This will help your doctor evaluate your results by marking the exact time that symptoms occurred.
  5. You may keep a log of all your activities and any symptoms.
  6. At the end of your Holter monitor test period, you will remove the electrodes. You will then return the device and your activity log to your doctor. The test period is usually 24–48 hours long.
  7. Your doctor will evaluate the Holter monitor results and discuss them with you.

What are the risks and potential complications of a Holter monitor?

A Holter monitor is a safe procedure. Some people may have minor skin irritation from the sticky electrodes. This generally goes away after removing the electrodes.

How do I prepare for my Holter monitor?

There is no special preparation needed for a Holter monitor test. However, it can be helpful to wear a loose-fitting, button-down top for comfort and convenience during the test period.

You may also wish to bathe or shower right before a Holter monitor test. You will be unable to shower during the test period because water damages the device.

Questions to ask your doctor

Patients often forget some of their questions about a Holter monitor during a doctor’s office appointment. You can contact your doctor with any concerns or questions before testing and between appointments.

It can also be a good idea to bring a list of questions to your appointments. Common questions include:

  • Why do I need a Holter monitor test?
  • How long will I wear the Holter monitor?
  • How should I take my medications before and after my Holter monitor test?
  • What kind of activities can I perform during the Holter monitor test?
  • What activities and symptoms do I need to document in my Holter monitor log?
  • When and how can I expect to get my results?
  • What other tests do I need?
  • When should I follow up with you?
  • How should I contact you? Ask for numbers to call during and after regular hours.

Learn what an EKG is.

What can I expect after my Holter monitor test?

Knowing what to expect after your Holter monitor test can help you return to normal activities as soon as possible.

How will I feel after my Holter monitor test?

You should not feel any ill effects or symptoms after your Holter monitor test. Tell your doctor or provider right away about any symptoms, such as:

When should I contact my doctor?

It is important to keep your follow-up appointments after your Holter monitor test. Contact your doctor for questions and concerns between appointments. Also let them know if you have any symptoms that are new, unusual, or are not responding to medication.

Seek emergency medical care or call 911 if you have chest pain or shortness of breath.

Other frequently asked questions

Here are some other commonly asked questions about Holter monitors.

How long do you usually wear a Holter monitor?

You usually wear a Holter monitor for 24–48 hours, but may need to wear it for up to 30 days.

How long does it take to get Holter monitor results?

A 2022 study recommends that clinicians interpret the results of a Holter monitor within 24 hours. This allows them to start treatment before any further cardiac events occur.

What can you do while wearing a Holter monitor?

You can live your life as you usually would with a Holter monitor. However, the following activities may interfere with the results:

  • spending time near magnets, metal detectors, and electrical appliances such as shavers, toothbrushes, and microwave ovens
  • wearing the monitor within 6 inches of a cell phone
  • using tobacco products
  • sweating excessively, which could cause the electrodes to detach


A Holter monitor can detect abnormal heartbeats and other heart changes that a standard EKG may miss. Because it is worn continuously for a longer period, it is more likely to detect abnormalities that occur periodically.

A Holter monitor helps your doctor diagnose and detect arrhythmias and decreased blood supply to your heart.

Was this helpful?
Medical Reviewer: Uzochukwu Ibe, MD, MPH
Last Review Date: 2022 Oct 31
View All Heart Health Articles
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.