What Are the Early Signs and Symptoms of AFib?

AFib Symptoms: Understanding the Warning Signs and Symptoms of Atrial Fibrillation

With contributions from Jeffrey R.

Symptoms of AFIBAtrial fibrillation (AFib) is a relatively common disorder. A study published in the Journal of the American College of Cardiology estimated that 2.7-6.1 million people in the United States have AFib, and that number is expected to grow with the aging population.

Of that estimation, approximately two percent of people who are younger than 65 have AFib, while nine percent of people who are older than 65 years old have AFib. And the risk of AFib increases with age.

One of the most interesting facts about AFib is that the people who are living with the condition do not know they have it because they are not experiencing any noticeable symptoms of the condition.

If you’re not – or if you are – experiencing the symptoms how can you reach a diagnosis of AFib? The first step to achieving a diagnosis is by learning the early signs and symptoms of AFib. By educating yourself about the symptoms, you and your healthcare team can work together to reach a diagnosis and develop a treatment to prevent progression of the condition.

What Causes AFib?

While AFib is also a bit mysterious: there are many AFib cases which are traced to an underlying disease or another heart condition, and sometimes there’s no discernable source as to how and why AFib developed.

While each case of diagnosing AFib is different, there are some conditions which are known to influence the development of AFib. These common causes of AFib may include:

  • High blood pressure
  • Heart diseases or conditions
  • Sleep apnea
  • Obesity
  • Diabetes
  • Lung diseases
  • Overactive thyroid
  • Genetics and/or age

Keep in mind these are just a few causes of AFib, and not a definite list.

Although it always involves an electrical misfiring in the heart’s atria, AFib can affect different people in many different ways.

What starts as a little heart flutter once in a while could turn into a regular occurrence in a matter of weeks, months or even years.

The Types of AFib

As atrial fibrillation worsens, you might notice more frequent AFib episodes, more symptoms, or more intense sensations in the chest or body. In some cases, intermittent AFib (known as paroxysmal AFib) will become persistent AFib, and perhaps even permanent AFib.

Here’s a quick lesson about the different types of AFib:

  • Intermittent/Occasional/Paroxysmal AFib. In this type of AFib, symptoms typically come and go, and may last for a few minutes to a few hours, and then stops on its own. Paroxysmal AFib can last up to 7 days.
  • Persistent AFib. With persistent AFib, the heart rhythm doesn’t go back to normal on its own. Treatment such as an electrical shock or medications will help the heart return to a regular rhythm. This type of AFib can last more than 7 days.
  • Long-standing persistent AFib. This type of AFib is continuous and lasts longer than 12 months.
  • Permanent AFib. Unfortunately, the abnormal heart rhythm from permanent AFib can’t be restored. A physician will prescribe you treatment to help prevent your condition from worsening.

Your physician can determine which type of AFib you have and provide proper treatment and guidance to help you manage the symptoms and the condition.

A good rule of thumb is to get any chest or heart discomfort checked out right away by a healthcare professional.

What Are Some Early AFib Symptoms to Watch for?

If AFib is indeed the source of your chest or heart discomfort symptoms, getting treatment started early can help prevent your AFib symptoms and condition from advancing or worsening, and that will immediately decrease your risk of stroke or heart failure in the future.

For the most part, atrial fibrillation can go undetected for a long time, but as it advances, many people eventually notice some abnormal sensations.

For example, pain isn’t the only worrisome chest symptom to watch out for – there are less prominent changes can also point to AFib. These other changes in the heart may include sensations of fluttering, palpitations, a racing heartbeat, unexplained and unusual fatigue levels, and a feeling of tightness in the chest.

Remember, if you experience any of these symptoms – seek out a healthcare professional as soon as possible to assess your symptoms for a proper diagnosis.

A Momentary Fluttering in the Chest

A little painless flutter in the chest or the feeling like your heart has just skipped a beat, usually is nothing to worry about and are often referred to as heart palpitations.

Heart palpitations are common, and are often very benign; a fright, moment of excitement, or bout of exercise could interrupt your heart’s natural rhythm.

However, when an unusual flutter or a pounding beat happens regularly – and without any discernable trigger – AFib may be to blame.

Forceful Heart Palpitations

While a flutter feels like a skipped beat, sometimes heart palpitations feel like hard and forceful heartbeats that are much stronger than usual. These palpitations are accompanied by a fast and irregular rhythm and are a classic sign of AFib.

People who have experienced a heart palpitation often describe it as feeling as though their heart is “jumping around inside their chest.”

A Racing or Sluggish Heartbeat

When your heart is in fibrillation, too many electrical signals are sent into your atria, and there they compete to get through the AV node (the gateway to your heart’s lower ventricles). This excess of electrical signals cause your atria to flutter, and can also speed up your heart rate.

You may notice your pulse is faster than usual or alternating between fast and slow.

Unusual Levels of Fatigue

When your heart’s atria aren’t moving efficiently, your tissues aren’t receiving as much oxygenated blood as they need. In turn, you may begin to feel tired, weak, and lethargic more than usual.

A racing heartbeat that goes on for too long is also physically exhausting, especially when it comes with an adrenaline response (which is common when anxiety is involved).

A Tight Sensation in the Chest

A tightness or constriction in the chest can signal something very serious, but it could also stem from a relatively harmless source.

If heartburn is to blame, an over-the-counter antacid may be enough to relieve the discomfort, but severe chest pressure that makes it difficult to breathe could be a signal of heart failure and demands swift medical attention.

AFib can sometimes cause a feeling of tightness in the chest as well, and though it’s not as much of an emergency as a heart attack, it certainly calls for a more in-depth investigation.

Other Discomforts Related to AFib Symptoms

As AFib progresses, symptoms will tend to hit at shorter intervals and may lead to other discomforts.

For instance, as your heart continues to lose efficiency, you may feel lightheaded or short of breath. Perhaps activities that were once easy for you are now quite strenuous, and you rarely feel well-rested, even after a full night’s sleep.


Next Page: Other warning signs and symptoms of AFib, is it AFib or something else? And more. 

What Are Some Other Warning Signs of AFib?

While the most noticeable symptoms of AFib can be obvious, there are also lesser-known signs of AFib. These early signs of AFib that can occur are based on numerous considerations like genetics and ethnic background, age, cardiac risk factors, and the type of AFib along with its primary cause.

Some of these other signs and symptoms of AFib are:

  • AFib reduces the amount of oxygen carried to the brain. The incomplete contractions of the atria don’t push their full volume of blood to the ventricles, which means that the ventricles are then unable to move enough oxygen-rich blood out to the rest of the body.A decreased amount of oxygen to the brain will lead to confusion along with impairment in cognitive abilities.
  • Throat tightness. Some individuals report the sensation of mild constriction in their throat and being able to feel their heart rate in that area.
  • Dizziness. As with confusion, a less than normal level of oxygen flow to the brain will cause dizziness, lightheadedness, and fainting.
  • Shortness of breath. AFib limits cardiac output, which decreases the transport of a healthy level of oxygen to the lungs. If you have AFib, you can experience shortness of breath with little or no activity.
  • Weakness or feeling faint. You can experience weakness at rest or during activity because your body’s muscles aren’t receiving the oxygen they need for fuel to perform at full strength.
  • Tiredness with exercise or activity. Reduced exercise tolerance is typical for people who have AFib. The heart’s standard response to physical activity is to increase its pumping speed to move more blood out to the working muscles to supply their increased demand for oxygen to fuel increased physical activity levels. With AFib, your heart rate can increase beyond a reasonable response to increased exertion without delivering enough energy, thus producing a faster onset of exercise-induced fatigue.
  • A rapid and uncontrolled heart rate for more than a brief period can also lead to associated physiological responses such as increased sweating and nausea. Some people with certain types of AFib have also reported abdominal pain and an increased need to urinate.


Any of these signs or symptoms can occur at rest or with different types of activity.

Warning signs of AFib worsen if you have other health problems like shortness of breath due to a respiratory issue, and active infection, hemorrhage, or sepsis. Significant emotional or physical stress and exhaustion from a lack of sleep can trigger or possibly worsen AFib symptoms.

Is it AFib or Something Else?

Some people describe AFib as a fluttering feeling, while others feel an ache or tightness. Palpitations can be soft or pronounced. In fact, symptoms can be so mild that you may not realize you have AFib until a doctor delivers the surprising news.

The point is that AFib can bear some resemblance to other conditions – some of which may occur simultaneously – including:

  • Anxiety or panic attack. The surge of adrenaline during an anxiety attack often leads to a full-body response, including painful or tight sensations in the chest and heart palpitations.
  • Lightheadedness or fatigue. Either of these issues can result from dehydration, a loss of blood volume, or generally poor physical conditioning.
  • Heartburn. Although many people will feel a “burning” sensation in their upper chest when too much stomach acid moves up the esophagus, heartburn could also manifest as pain (some may even mistake it for a heart attack).
  • Hyperthyroidism. When the thyroid gland produces too much thyroid hormone, it stimulates your metabolism, leading to anxiety, irritability, and hypertension. In some people, hyperthyroidism can also lead to heart palpitations, a rapid heart rate, and breathlessness.
  • Heart attack. The difference in symptoms between the two conditions is that AFib often occurs suddenly with a fluttering feeling and chest palpitations, whereas a heart attack starts gradually and includes intense chest pain that can spread to the shoulders, arms, back, up into the neck and jaw, and in some instances the abdominal region. Although having a heart attack can cause AFib, but the arrhythmia will not lead to a heart attack.
  • Heart disorders. Not surprisingly, other heart disorders can mimic AFib, particularly sinus arrhythmia, and various forms of tachycardia. In fact, a heart valve disorder or coronary artery disease could be the source of your AFib and will need to be diagnosed and dealt with before your AFib symptoms can be eliminated.
  • Other physiologic ailments. Conditions such as anemia, an electrolyte imbalance, changes in hormones, or low blood glucose levels can also cause specific symptoms seen with AFib.

Keep in mind that even if you don’t have any symptoms, the fact that you have AFib places you at a five times higher likelihood for stroke than someone with no history of AFib.

Because of this circumstance, people with AFib need to understand the signs and symptoms of stroke, which include drooping on one side of your face, arm weakness on one side, and difficulty speaking or understanding someone who is talking. If any of these symptoms occur at any time, you need to call 911 immediately.

Although only a qualified medical professional can provide an accurate diagnosis, certain symptom sets most likely point to AFib instead of one of these mimicking conditions.

For instance, a sudden, severe, and short-lived response could signal a major event like a heart attack, or perhaps an anxiety attack; AFib is often marked by fluctuating symptoms, cycles of “episodes” that eventually end and begin again (unless you live with permanent AFib).

How Is AFib Diagnosed?

The AFib diagnosis procedure is relatively straightforward. If your symptoms are persistent and you suspect you may be in AFib most of the time, your doctor will first conduct an electrocardiogram (EKG or ECG) to evaluate your heart rhythm over the course of a few minutes.

However, If your symptoms come less frequently, you may instead wear a Holter monitor for 24 to 48 hours in order to catch the next AFib episode.

Your doctor can also order a chest x-ray and echocardiogram to assess your heart function and see if there are any unusual problems such as a reduced pumping capacity often known as heart failure.

There are a variety of other tests that can be helpful if these initial investigations don’t show any problems. The key is to be clear and thorough when you report the symptoms you are experiencing and when they appear to your doctor, so they have a good idea of how your AFib may be triggered or aggravated.

The more detailed you can describe how your symptoms affect your life, the more personal and targeted your testing and treatment plan will be.

Your blueprint will take into account your previous medical history, your age and specific genetics, the presence of any other underlying cardiac conditions or risk factors that would cause them, and the type of AFib you have.

Not all individuals who have AFib experience symptoms. According to a study in the American Heart Association journal Circulation from 2012, roughly 15 to 30 percent of people with AFib show no signs of the condition.

In some cases, AFib doesn’t appear until a person has a routine EKG, other medical procedure that requires heart rhythm monitoring, or after a stroke.

When to See a Doctor

If you feel any of the adverse signs or symptoms mentioned earlier, seek medical attention as soon as possible. Early detection of AFib will give your healthcare team the best chance of developing an effective treatment plan before your condition worsens.


StopAfib.org (How Atrial Fibrillation Progresses)

MedicineNet (Patient Comments: Atrial Fibrillation – Symptoms and Signs)

Health.com (11 Surprising Symptoms of Acid Reflux)

Right Diagnosis (Misdiagnosis of Atrial Fibrillation)

Centers for Disease Control and Prevention (Atrial Fibrillation Fact Sheet)

Heart.org (What are the Symptoms of Atrial Fibrillation – Afib or AF?)

WebMD (Signs and Symptoms of Atrial Fibrillation)

Mayo Clinic (Atrial fibrillation – Symptoms and causes)

Heart Rhythm Society (Symptoms and Warning Signs)

Thrombosis Advisor (Signs and Symptoms of Atrial Fibrillation)

AHA Journals (Symptoms and Functional status of Patients With Atrial Fibrillation)

University of Michigan – Michigan Health (Other Conditions With Symptoms Similar To Atrial Fibrillation)

Journal of the American College of Cardiology (2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation)

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Angela FinlayAngela Finlay

Angela is a freelance writer and blogger committed to learning, understanding and communicating about the matters that affect daily life. From fitness and lifestyle, pregnancy and medical ailments, she has covered a range of health topics throughout her web writing career, contributing to major websites for over three years.

May 22, 2018
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