Endocarditis: Symptoms, Causes, Types, Diagnosis, Treatment and When to Seek Emergency Care — What You Need to Know
Updated: 2 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: September 2026
TL;DR — Key Facts at a Glance
Endocarditis is inflammation of the inner lining of your heart valves and chambers. It is most often caused by a bacterial infection and can be fatal without treatment. With quick, aggressive treatment — usually several weeks of IV antibiotics and sometimes surgery — most people survive. This article uses only figures published by the authoritative source page; the source provides no prevalence or incidence statistics for endocarditis, and no invented statistics appear anywhere in this article.
What it is: inflammation of the inner lining (endocardium) of the heart valves and chambers, featuring growths called vegetations.
Most common cause: bacterial infection — germs enter the bloodstream and attach to damaged areas of the heart.
Main types: infective (most common) and non-infective (much rarer, "sterile" vegetations).
Two speeds: acute (sudden, life-threatening within days) and subacute (develops gradually over weeks to months).
Standard treatment: IV antibiotics for several weeks — usually up to six — plus surgery if the heart valve is damaged.
Antibiotic course: typically two to eight weeks to fully clear the infection.
Survival: most people survive when they receive aggressive treatment; without treatment, endocarditis can be fatal.
Prevention: not always preventable; prophylactic antibiotics are recommended before certain dental procedures for high-risk people.
Quick Answer: What Is Endocarditis?
Endocarditis is inflammation of the inner lining of your heart valves and chambers — tissue called the endocardium. It most often starts when bacteria enter your bloodstream from another part of your body, travel to your heart, and attach to damaged heart tissue. There, they multiply and form growths called vegetations, which break down the surrounding heart tissue and can badly damage your heart valves.
The two main types are infective endocarditis (by far the most common, often called bacterial endocarditis) and non-infective endocarditis (much rarer, caused by conditions that make the blood clot too easily). Symptoms can include fever above 100°F (38.4°C), chills, night sweats, chest pain, a new heart murmur, fast heart rate, fatigue, and shortness of breath. If you develop these symptoms, go to the emergency room — infective endocarditis is life-threatening. Treatment usually involves IV antibiotics for several weeks and sometimes heart valve surgery.
What Is Endocarditis?
Endocarditis is inflammation of the inner lining of your heart valves and chambers, known as the endocardium. The hallmark of the condition is the formation of growths in the heart's lining called vegetations, and these growths can cause serious damage to your heart tissue.
In infective endocarditis — the most common type — germs (usually bacteria) enter your bloodstream, attach to damaged areas inside your heart, and multiply. Over time, the continuing inflammation allows the vegetations to break down the surrounding heart tissue, which can greatly damage your heart valves (see our guide to heart valve disease).
What are vegetations?
In infective endocarditis, vegetations are composite growths made of three components. Understanding what they are built from helps explain why they persist and why treatment requires weeks of antibiotics.
Infecting organisms: the bacteria or fungi causing the infection.
Fibrin: a protein that plays a role in blood clotting.
Platelets: tiny cell fragments in your blood.
What Are the Types of Endocarditis?
There are two main types of endocarditis, and they differ sharply in how common they are and what causes them.
Infective endocarditis (bacterial endocarditis)
Infective endocarditis happens when germs — usually bacteria — attach to damaged heart tissue. This is the most common type of endocarditis, and healthcare providers may also call it bacterial endocarditis (BE). Its vegetations are built from the infecting organisms (bacteria or fungi), fibrin, and platelets, as described above.
Infective endocarditis comes in two forms that differ in how quickly they strike:
Acute: begins suddenly with a high fever and fast heart rate, and can become life-threatening within days.
Subacute: develops gradually over weeks or several months, and is still dangerous without prompt treatment.
Non-infective endocarditis (sterile vegetations)
Non-infective endocarditis is much rarer. It involves vegetations in the heart's lining that are not caused by an infection — hence the name sterile vegetations.
This type is linked to conditions that make your blood clot too easily, known as a hypercoagulable state. Two examples are antiphospholipid syndrome and lupus (systemic lupus erythematosus). Healthcare providers may use several other names for this type, including:
Libman-Sacks endocarditis
Non-bacterial thrombotic endocarditis (NBTE)
Marantic endocarditis
Notably, non-infective endocarditis typically causes no symptoms of its own. Most people do not know they have it until vegetations show up on heart imaging tests performed for other reasons, or as an unexpected finding in an autopsy. Any symptoms present are usually those of the underlying condition causing it, such as lupus.
What Are the Symptoms of Endocarditis?
Symptoms of infective endocarditis can vary, but the source lists twelve recognized warning signs. Because this condition is life-threatening, prompt recognition matters.
Chest pain — a warning sign requiring urgent evaluation.
Heart murmur — an abnormal whooshing sound heard during a heartbeat.
Fast heart rate (tachycardia) — especially prominent in the acute form.
Fatigue — persistent tiredness.
Fever above 100°F (38.4°C) — a high fever is typical of acute onset.
Chills and night sweats — often accompany the fever.
Loss of appetite and weight loss — more common in the slower subacute form.
Muscle and joint aches — widespread aching pain.
Shortness of breath (dyspnea) — indicates the heart is struggling.
Skin rash — can signal the infection is affecting blood vessels.
Swelling in your abdomen or legs — a sign of fluid buildup from heart strain.
Blood in your urine (hematuria) — reflects how widely the infection can spread.
Go to the emergency room if you have these symptoms. Infective endocarditis is life-threatening.
What Causes Endocarditis?
Most of the time, a bacterial infection causes endocarditis. The bacteria originate elsewhere in your body — for example, in your mouth, on your skin, or in your respiratory system — and then travel through your bloodstream to your heart.
Why does the bacteria attach to the heart?
Healthy heart tissue is normally very resistant to infection. However, underlying damage makes endocarditis more likely to develop. Once bacteria reach the damaged tissue, they attach and grow there, forming vegetations and producing enzymes that destroy the surrounding heart tissue.
What Increases Your Risk of Endocarditis?
Endocarditis isn't very common in the general population, but several factors raise your risk considerably:
Artificial heart valve, pacemaker, or defibrillator: foreign material in the heart gives bacteria a surface to cling to.
Heart conditions: especially heart valve disease and hypertrophic cardiomyopathy.
Previous bacterial endocarditis: a past episode increases the chance of another.
Previous heart valve surgery: surgical repair can leave areas vulnerable to infection.
IV substance use: directly introduces germs into the bloodstream.
Poor dental health and gum disease: the mouth is a common starting point for the bacteria involved (see our guide to periodontitis).
Diabetes: can weaken the body's ability to fight infection.
Weakened immune system: reduces defenses against bloodstream bacteria.
What Complications Can Endocarditis Cause?
Without early diagnosis and treatment, endocarditis can lead to serious and potentially fatal complications. The source identifies eight specific complications:
Abnormal heart rhythm (arrhythmia): disrupts the heart's normal electrical signaling.
Abscesses around heart valves: pockets of infection that can destroy local tissue.
Heart block: electrical conduction in the heart is impaired.
[Heart failure](https://www.rinnit.com/post/heart-failure-symptoms-causes-treatment-guide): the heart can no longer pump blood effectively.
Leaky heart valve: the valve fails to close properly, allowing backflow.
[Sepsis](https://www.rinnit.com/post/rinnit-sepsis-complete-guide): a body-wide, life-threatening response to infection.
[Stroke](https://www.rinnit.com/post/stroke-symptoms-causes-diagnosis-and-treatment-a-complete-guide): vegetation fragments can travel to the brain.
Death: endocarditis can be fatal without treatment.
How Is Endocarditis Diagnosed?
If you have symptoms and risk factors for endocarditis, your healthcare provider will want to make a diagnosis as soon as possible. Diagnosis combines blood tests that detect infection with imaging tests that reveal vegetations and heart damage.
Which blood tests are used?
Bacterial culture test: identifies the specific bacteria in your bloodstream.
Complete blood count (CBC): measures overall blood cell levels, including infection markers.
C-reactive protein (CRP) test: measures inflammation in the body.
Which imaging tests are used?
Imaging tests can show vegetations and heart damage directly. Your provider may recommend one or more of the following:
Echocardiogram: uses sound waves to create images of your heart from the outside of the chest.
Transesophageal echocardiogram (TEE): captures detailed images from inside the esophagus, close to the heart.
Heart MRI: provides detailed pictures of heart structure and any damage.
What Is the Treatment for Endocarditis?
Endocarditis can be life-limiting, which is why quick treatment is essential to prevent damage to your heart valves and more serious complications.
IV antibiotics: the foundation of treatment
The core treatment is IV antibiotics delivered over several weeks — usually up to six — to fully clear the infection. Once laboratory results identify the exact bacteria at play, your provider may adjust the antibiotic selection for a better match.
Throughout your therapy, your provider will check your symptoms to confirm the treatment is working. They will also repeat your blood cultures to verify that the bloodstream infection has cleared.
When is surgery needed?
If endocarditis damages your heart valve and any other part of your heart, you may need surgery to repair or replace the damaged valve.
What Can You Expect During Recovery?
You can expect to take antibiotics for two to eight weeks to get rid of the infection. Most people survive endocarditis when they receive aggressive treatment.
However, the risk of serious complications or death varies from person to person and depends on five factors:
Your age: older age generally raises risk.
Artificial valve: having one increases complication risk.
Duration of infection: longer-standing infection worsens prognosis.
Type of organism: some bacteria are more aggressive than others.
Extent of heart valve damage: more damage means higher risk.
Your healthcare provider can give you a better idea of what to expect based on your specific situation.
Can Endocarditis Be Prevented?
Endocarditis isn't always preventable. However, if you're at high risk for it or have had it before, your healthcare provider will likely recommend taking prophylactic (preventive) antibiotics before certain dental procedures.
Which dental procedures require preventive antibiotics?
Your gums: deep cleanings and gum surgery.
The periapical (root) area of your teeth: root canal and related procedures.
Your oral mucosa: the tissue that lines the inside of your mouth.
What should high-risk people do?
The source recommends two practical steps for anyone whose heart condition places them at greater risk. First, tell your medical and dental providers that you have heart disease that raises your endocarditis risk. Second, carry a wallet identification card with specific antibiotic guidelines — the American Heart Association offers these cards.
When Should You Go to the Emergency Room?
Infective endocarditis is life-threatening. Go to the emergency room right away — or call emergency services — if you develop symptoms such as chest pain, a new heart murmur, fast heart rate, fever above 100°F (38.4°C), chills, night sweats, loss of appetite and weight loss, muscle and joint aches, shortness of breath, skin rash, swelling in your abdomen or legs, or blood in your urine.
Do not wait for symptoms to improve on their own. Every day without treatment increases the risk of permanent heart valve damage, stroke, sepsis, and death.
What Questions Should You Ask Your Healthcare Provider?
Preparing questions ahead of time helps you get the most out of your appointment. Consider asking:
Which type of endocarditis do I have — infective or non-infective?
What bacteria caused my infection, and is the antibiotic matched to it?
How long will my IV antibiotic treatment last?
Will I need heart valve surgery, and when?
What complications should I watch for during treatment?
Am I at higher risk of getting endocarditis again?
Do I need preventive antibiotics before dental work?
Can I get an American Heart Association wallet identification card?
Conclusion: Act Fast, Because Most People Recover With Aggressive Treatment
Endocarditis is a serious, potentially fatal inflammation of your heart's inner lining — but it is also highly treatable when caught early. The source page emphasizes this clearly: with aggressive treatment, most people recover. The key is recognizing the warning signs — fever above 100°F (38.4°C), chills, night sweats, chest pain, a fast heart rate, a new heart murmur — and seeking emergency care immediately rather than hoping symptoms pass.
"With aggressive treatment, most people recover from endocarditis. Know the symptoms of endocarditis and go to the ER right away if you think you have it. Taking good care of your teeth and mouth can lower your risk of endocarditis. That includes daily care, as well as visiting your dental provider regularly."
Your next steps:
Go to the ER right away if you have endocarditis symptoms — infective endocarditis is life-threatening and every day counts.
Commit to the full antibiotic course (typically two to eight weeks) and attend every follow-up, including repeat blood cultures.
Protect your teeth and mouth daily — good oral hygiene and regular dental visits lower your risk, and preventive antibiotics before certain dental procedures add extra protection if your provider recommends them.
This article provides general health information for educational purposes and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider about any health condition.
Frequently Asked Questions (FAQ)
What is endocarditis?
Endocarditis is inflammation of the inner lining (endocardium) of your heart valves and chambers, most often caused by a bacterial infection. It can be fatal without treatment.
Is endocarditis contagious?
No. Endocarditis is not contagious from person to person. It occurs when germs already present in your own body — from your mouth, skin, or respiratory system — travel through your bloodstream to your heart.
What causes endocarditis?
Most of the time, a bacterial infection causes it. Bacteria from elsewhere in your body travel through your blood, attach to damaged areas of your heart, grow vegetations, and produce enzymes that destroy surrounding heart tissue.
Who is at highest risk for endocarditis?
People with artificial heart valves, pacemakers, or defibrillators; those with heart conditions like heart valve disease or hypertrophic cardiomyopathy; people with previous bacterial endocarditis or previous heart valve surgery; IV substance users; people with poor dental health or gum disease; people with diabetes; and people with weakened immune systems.
What are the symptoms of infective endocarditis?
Symptoms include chest pain, heart murmur, fast heart rate, fatigue, fever above 100°F (38.4°C), chills and night sweats, loss of appetite and weight loss, muscle and joint aches, shortness of breath, skin rash, swelling in the abdomen or legs, and blood in the urine.
When should I go to the ER for endocarditis symptoms?
Go to the emergency room right away if you have these symptoms. Infective endocarditis is life-threatening, and emergency care should not be delayed.
How quickly can endocarditis become dangerous?
The acute form begins suddenly with a high fever and fast heart rate and can become life-threatening within days. The subacute form develops gradually over weeks or several months.
What are vegetations in endocarditis?
Vegetations are growths that form in the heart's lining. In infective endocarditis, they are made of infecting organisms (bacteria or fungi), fibrin (a blood-clotting protein), and platelets (tiny blood cell fragments).
Can vegetations damage my heart?
Yes. As inflammation continues, vegetations break down the surrounding heart tissue, which can greatly damage your heart valves.
What is the difference between acute and subacute endocarditis?
Acute endocarditis begins suddenly with a high fever and fast heart rate and can become life-threatening within days. Subacute endocarditis develops gradually over weeks or several months.
What is non-infective endocarditis?
Non-infective endocarditis is a much rarer type involving vegetations in the heart's lining that are not caused by an infection — called sterile vegetations. It is linked to conditions that make blood clot too easily, such as antiphospholipid syndrome and lupus.
Does non-infective endocarditis have symptoms?
Typically not. Most people don't know they have it until vegetations appear on heart imaging tests done for other reasons, or as an autopsy finding. Any symptoms are usually those of the underlying condition.
What are the other names for non-infective endocarditis?
Libman-Sacks endocarditis, non-bacterial thrombotic endocarditis (NBTE), and marantic endocarditis.
How is endocarditis diagnosed?
Through blood tests — bacterial culture, complete blood count, and C-reactive protein (CRP) — plus imaging tests that can show vegetations and heart damage, including an echocardiogram, transesophageal echocardiogram (TEE), and heart MRI.
What is a transesophageal echocardiogram (TEE)?
A TEE is an imaging test that captures detailed pictures of the heart from inside the esophagus, close to the heart, to detect vegetations and damage that a standard echocardiogram might miss.
How is endocarditis treated?
Treatment centers on IV antibiotics for several weeks — usually up to six — to fully treat the infection. The antibiotic may be adjusted once the specific bacteria is identified. If the heart valve is damaged, surgery may be needed.
How long do I take antibiotics for endocarditis?
You can expect to take antibiotics for two to eight weeks to fully clear the infection.
How long does endocarditis treatment take?
Most people need up to six weeks of IV antibiotics. Providers monitor symptoms throughout and repeat blood cultures to confirm the infection has cleared.
Do I need surgery for endocarditis?
Only if endocarditis damages your heart valve and other parts of your heart. Your provider will determine whether surgery is necessary based on the extent of the damage.
Will I survive endocarditis?
Most people survive endocarditis when they get aggressive treatment. Without treatment, however, endocarditis can be fatal.
What determines my risk of complications or death from endocarditis?
Five factors: your age, whether you have an artificial valve, how long you've had the infection, what type of bacteria made you sick, and how badly your heart valve is damaged.
What complications can endocarditis cause if left untreated?
Abnormal heart rhythm (arrhythmia), abscesses around heart valves, heart block, heart failure, a leaky heart valve, sepsis, stroke, and death.
Can endocarditis be prevented?
Not always. But if you're at high risk or have had it before, your provider will likely recommend prophylactic (preventive) antibiotics before certain dental procedures that involve your gums, the root area of your teeth, or the oral mucosa.
Which dental procedures require preventive antibiotics?
Procedures involving your gums, the periapical (root) area of your teeth, and the oral mucosa — the tissue lining the inside of your mouth.
Should I tell my dentist about my heart condition?
Yes. Tell your medical and dental providers you have heart disease that places you at greater risk for endocarditis. Carry a wallet identification card with specific antibiotic guidelines — the American Heart Association offers these.
Does good oral hygiene really help prevent endocarditis?
Yes. Taking good care of your teeth and mouth can lower your risk of endocarditis, including daily care and visiting your dental provider regularly.
Can endocarditis come back?
Yes — having had previous bacterial endocarditis or previous heart valve surgery both count as risk factors, which is why preventive antibiotics are recommended for high-risk people before certain dental procedures.
What should I ask my healthcare provider about endocarditis?
Ask which type you have, what bacteria caused it, how long treatment will last, whether you need surgery, what complications to watch for, and whether you need preventive antibiotics before dental work.
References
American Heart Association. Infective Endocarditis (last reviewed 8/1/2024)
Ibrahim AM, Siddique MS. Libman-Sacks Endocarditis. StatPearls (2023)
Merck Manual Consumer Version. Infective Endocarditis (last revised 7/2024)
National Heart, Lung, and Blood Institute (U.S.). Endocarditis (last updated 10/10/2023)
Venepally NR, et al. A New Insight Into Nonbacterial Thrombotic Endocarditis: A Systematic Review of Cases. Anatol J Cardiol (2022 Oct;26(10):743-749)
Yallowitz AW, Decker LC. Infectious Endocarditis. StatPearls (2023)
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