Medically reviewed on March 6, 2018
Endocarditis is an infection of the endocardium, which is the inner lining of your heart chambers and heart valves.
Endocarditis generally occurs when bacteria, fungi or other germs from another part of your body, such as your mouth, spread through your bloodstream and attach to damaged areas in your heart. If it's not treated quickly, endocarditis can damage or destroy your heart valves and can lead to life-threatening complications. Treatments for endocarditis include antibiotics and, in certain cases, surgery.
Since there are many ways to develop endocarditis, your doctor might not be able to pinpoint the exact cause of your condition. However, people at greatest risk of endocarditis usually have damaged heart valves, artificial heart valves or other heart defects.
Endocarditis occurs when bacteria enter your bloodstream, travel to your heart, and lodge on abnormal heart valves or damaged heart tissue. Abnormal growths (vegetations) that contain collections of bacteria may form in your heart at the site of the infection and damage the heart valves, which can cause them to leak.
Endocarditis may develop slowly or suddenly, depending on what germs are causing the infection and whether you have any underlying heart problems. Endocarditis signs and symptoms can vary from person to person.
Common signs and symptoms of endocarditis include:
- Flu-like symptoms, such as fever and chills
- A new or changed heart murmur, which is the heart sounds made by blood rushing through your heart
- Aching joints and muscles
- Night sweats
- Shortness of breath
- Chest pain when you breathe
- Swelling in your feet, legs or abdomen
Endocarditis can also cause symptoms that are more uncommon. These include:
- Unexplained weight loss
- Blood in your urine, which you might be able to see or that your doctor might see when he or she views your urine under a microscope
- Tenderness in your spleen, which is an infection-fighting abdominal organ just below your rib cage on the left side of your body
- Janeway lesions, which are red spots on the soles of your feet or the palms of your hands
- Osler's nodes, which are red, tender spots under the skin of your fingers or toes
- Petechiae (puh-TEE-key-e), which are tiny purple or red spots on the skin, whites of your eyes, or inside your mouth
When to see a doctor
If you develop signs or symptoms of endocarditis, and if they don't go away, see your doctor as soon as possible — especially if you have risk factors for this serious infection, such as a heart defect or a previous case of endocarditis.
Although less serious conditions can cause similar signs and symptoms, you won't know for sure until you're evaluated by your doctor.
Endocarditis occurs when germs enter your bloodstream, travel to your heart, and attach to abnormal heart valves or damaged heart tissue. Certain types of bacteria cause most cases, but fungi or other microorganisms also may be responsible.
Usually, your immune system destroys harmful bacteria that make it into your bloodstream. Even if bacteria reach your heart, they may pass through without causing an infection. However, bacteria that live in your mouth, throat or other parts of your body, such as your skin or your gut, can sometimes cause serious infections like endocarditis under the right circumstances.
Bacteria, fungi or other germs that cause endocarditis might enter your bloodstream through:
- Everyday oral activities. Activities such as brushing your teeth, or other activities that could cause your gums to bleed, can allow bacteria to enter your bloodstream — especially if you don't floss or your teeth and gums aren't healthy.
- An infection or other medical condition. Bacteria may spread from an infected area, such as a skin sore. Other medical conditions, such as gum disease, a sexually transmitted infection or certain intestinal disorders — such as inflammatory bowel disease — can also give bacteria the opportunity to enter your bloodstream.
- Catheters. Bacteria can enter your body through a catheter — a thin tube that doctors sometimes use to inject or remove fluid from the body. This is more likely to occur if the catheter is in place for a long period of time.
- Needles used for tattoos and body piercing. The bacteria that can cause endocarditis can also enter your bloodstream through the needles used for tattooing or body piercing.
- Intravenous (IV) illegal drug use. Contaminated needles and syringes are a special concern for people who use illegal intravenous (IV) drugs, such as heroin or cocaine. Often, individuals who use these types of drugs don't have access to clean, unused needles or syringes.
- Certain dental procedures. Some dental procedures that can cut your gums may allow bacteria to enter your bloodstream.
Bacteria can more easily attach to the lining of your heart (endocardium), if the lining's surface is rough. You're also more likely to develop endocarditis if you have faulty, diseased or damaged heart valves. However, endocarditis does occasionally occur in previously healthy individuals.
If your heart is healthy, you could be less likely to develop endocarditis, although it is still possible. The germs that cause infection tend to stick to and multiply on damaged or surgically implanted heart valves, or on endocardium that has a rough surface.
People at highest risk of endocarditis are those who have:
- Artificial heart valves. Germs are more likely to attach to an artificial (prosthetic) heart valve than to a normal heart valve.
- Congenital heart defects. If you were born with certain types of heart defects, such as an irregular heart or abnormal heart valves, your heart may be more susceptible to infection.
- A history of endocarditis. Endocarditis can damage heart tissue and valves, increasing the risk of a future heart infection.
- Damaged heart valves. Certain medical conditions, such as rheumatic fever or infection, can damage or scar one or more of your heart valves. This can make them more prone to endocarditis.
- A history of intravenous (IV) illegal drug use. People who use illegal drugs by injecting them are at a greater risk of endocarditis. The needles used to inject drugs can be contaminated with the bacteria that can cause endocarditis.
A normal heart has two upper and two lower chambers. The upper chambers, the right and left atria, receive incoming blood. The lower chambers, the more muscular right and left ventricles, pump blood out of your heart. The heart valves, which keep blood flowing in the right direction, are gates at the chamber openings.
In endocarditis, clumps of bacteria and cell fragments form in your heart at the site of the infection. These clumps, called vegetations, can break loose and travel to your brain, lungs, abdominal organs, kidneys or limbs. As a result, endocarditis can cause several major complications, including:
- Heart problems, such as heart murmur, heart valve damage and heart failure
- Loss of the ability to move part of all of your body (paralysis)
- Pockets of collected pus (abscesses) that develop in the heart, brain, lungs and other organs
- Pulmonary embolism — an infected vegetation that travels to the lungs and blocks a lung artery
- Kidney damage
- Enlarged spleen
You can help prevent endocarditis in several ways, including:
- Know the signs and symptoms of endocarditis. See your doctor immediately if you develop any signs or symptoms, especially a fever that won't go away, unexplained fatigue, any type of skin infection, or open cuts or sores that don't heal properly.
- Pay special attention to your dental health — brush and floss your teeth and gums often, and have regular dental checkups.
- Avoid procedures that may lead to skin infections, such as body piercings or tattoos.
Certain dental and medical procedures may allow bacteria to enter your bloodstream. For some people with heart disease or damaged or diseased heart valves, taking antibiotics before these procedures can help destroy or control the harmful bacteria that may lead to endocarditis. This is because these people are more at risk of developing endocarditis after having these procedures.
In the past, doctors gave antibiotics to many people before dental or other surgical procedures, such as procedures involving the intestinal or urinary tracts, even if they weren't at high risk of developing endocarditis. However, antibiotics are no longer recommended before all dental or other surgical procedures, or for all people. As doctors have learned more about endocarditis prevention, they've realized endocarditis is much more likely to occur from exposure to random germs than from a standard dental exam or surgery.
If you're at risk of endocarditis, let your doctor and dentist know before having any dental work. They will decide whether you need antibiotics before any dental procedures.
It's still important to take good care of your teeth through brushing and flossing, since doctors have some concern that infections in your mouth from poor oral hygiene might increase the risk of germs entering your bloodstream. In addition to brushing and flossing, regular dental exams are an important part of maintaining good oral health.
Your doctor may suspect endocarditis based on your medical history, signs and symptoms you're experiencing, and your test results. A diagnosis of endocarditis is usually based on several factors instead of a single positive test result or symptom.
Your doctor may order several tests to help make a positive diagnosis, including:
- Blood tests. A blood culture test is used to identify any bacteria or fungi in your bloodstream, and it's the most important test your doctor will perform. Blood tests can also help your doctor identify certain conditions that can be a sign of endocarditis, such as anemia — a shortage of healthy red blood cells.
Echocardiogram. An echocardiogram uses sound waves to produce images of your heart while it's beating. This test is often used to check for signs of infection. Your doctor may use two different types of echocardiograms to help diagnose endocarditis.
In a transthoracic echocardiogram, sound waves directed at your heart from a wandlike device (transducer) held on your chest produce video images of your heart in motion. This test can help your doctor look at your heart's structure and check it for any signs of infection or damage.
Doctors may conduct another type of echocardiogram called a transesophogeal echocardiogram to get a closer look at your heart valves. During this test, a small transducer attached to the end of a tube is inserted down the tube leading from your mouth to your stomach (esophagus). This test can allow your doctor to get much more detailed pictures of your heart than is possible with a transthoracic echocardiogram.
- Electrocardiogram (ECG). While an ECG isn't specifically used to diagnose endocarditis, it can show your doctor if something is affecting your heart's electrical activity. During an ECG, sensors that can detect your heart's electrical activity are attached to your chest, arms and legs. This test is used to measure the timing and duration of each electrical phase in your heartbeat.
- Chest X-ray. X-ray images help your doctor see the condition of your lungs and heart. Your doctor can use X-ray images to see if endocarditis has caused your heart to enlarge or if any infection has spread to your lungs.
- Computerized tomography (CT) scan or magnetic resonance imaging (MRI). You may need a CT scan or an MRI scan of your brain, chest or other parts of your body if your doctor thinks that infection has spread to these areas.
Many cases of endocarditis are successfully treated with antibiotics. Sometimes, surgery may be required to fix damaged heart valves and clean up any remaining signs of the infection.
If you have endocarditis, your doctor might recommend high doses of intravenous (IV) antibiotics in the hospital. Your doctor will use blood culture tests to help identify the organism that's causing your infection. Based on the results of your blood tests, your doctor will choose the most appropriate antibiotic or combination of antibiotics to fight the infection.
You'll generally spend a week or more in the hospital when you start taking IV antibiotics. This gives your doctor time to see if the antibiotics are working against your infection. You'll usually take antibiotics for several weeks to clear up the infection.
Once your fever and the worst of your signs and symptoms have passed, you might be able to leave the hospital and continue IV antibiotic therapy with visits to your doctor's office or at home with home-based care. You'll still need to see your doctor regularly to make sure your treatment is working.
It's important to tell your doctor about any signs or symptoms that may mean your infection is getting worse, such as:
- Joint pain
- Shortness of breath
Also, if you develop diarrhea, a rash, itching or joint pain, let your doctor know as soon as possible. These signs and symptoms may indicate you're having a reaction to your prescribed antibiotic.
If you have shortness of breath or swelling in your legs, ankles or feet after you start antibiotic treatment, see your doctor immediately. These signs and symptoms can be indicators of heart failure.
If the infection damages your heart valves, you may have symptoms and complications for years after treatment. Sometimes surgery is needed to treat persistent infections or to replace a damaged valve. Surgery is also sometimes needed to treat endocarditis that's caused by a fungal infection.
Depending on your condition, your doctor may recommend either repairing your damaged valve or replacing it with an artificial valve made of cow, pig or human heart tissue (biological tissue valve) or man-made materials (mechanical valve).
Lifestyle and home remedies
If you're at risk of endocarditis, let all of your health care providers know. You may want to request an endocarditis wallet card from the American Heart Association. Check with your local chapter or print the card from the association's website.
Preparing for an appointment
The first doctor you see will likely be your family doctor or an emergency room physician. Or, when you call to set up an appointment, you may be referred to a doctor trained in diagnosing and treating heart conditions (cardiologist).
What you can do
You can help prepare for your appointment by taking these steps:
- Write down any symptoms you're experiencing. Be sure to note how long you've had particular symptoms. If you've had similar symptoms that have come and gone in the past be sure to include that information.
- Make a list of your key medical information. Your doctor will need to know about any other recent health problems you've had and the names of all prescription and over-the-counter medications and supplements you're taking.
- Find a family member or friend who can come with you to the appointment. Someone who accompanies you can help remember what your doctor says.
It's also important to write down any questions you might have before you get to your appointment. For endocarditis, some basic questions you might want to ask your doctor include:
- What's the most likely cause of my symptoms?
- What kinds of tests do I need? How do I need to prepare for the tests?
- What treatment do you recommend?
- How soon after I begin treatment will I start to feel better?
- What are the possible side effects?
- Am I at risk of long-term complications from this condition? Will it come back?
- How often will I need follow-up for this condition?
- Do I need to take preventive antibiotics for certain medical or dental procedures?
- I have other medical conditions. How can I best manage these conditions together?
What to expect from your doctor
Your doctor will probably ask you many questions, including:
- What are your symptoms?
- When did your symptoms start? Did they come on suddenly or more gradually?
- Have you had similar symptoms in the past?
- Are you having difficulty breathing?
- Have you recently had an infection?
- Have you recently had a fever?
- Have you recently had any medical or dental procedures that used needles or catheters?
- Have you ever used intravenous drugs?
- Have you recently lost weight without trying?
- Have you been diagnosed with any other medical conditions, especially heart murmurs?
- Do any of your first-degree relatives — such as parents, siblings or children — have a history of heart disease?