Causes

Endocarditis occurs when germs, usually bacteria, enter your bloodstream, travel to your heart, and attach to abnormal heart valves or damaged heart tissue. Fungi or other germs also may cause endocarditis.

Usually, your immune system destroys any harmful bacteria that enter your bloodstream. However, bacteria that live in your mouth, throat or other parts of your body, such as your skin or your gut, can sometimes cause endocarditis under the right circumstances.

Bacteria, fungi and other germs that cause endocarditis might enter your bloodstream through:

• Improper dental care. Proper toothbrushing and flossing helps prevent gum disease. If you don't take good care of your teeth and gums, brushing could cause unhealthy gums to bleed, giving bacteria a chance to enter your bloodstream. Some dental procedures that can cut your gums also may allow bacteria to enter your bloodstream.
• Catheters. Bacteria can enter your body through a thin tube that doctors sometimes use to inject or remove fluid from the body (catheter). This is more likely to occur if the catheter is in place for a long period of time. For example, you may have a catheter if you need long-term dialysis.
• Illegal IV drug use. Contaminated needles and syringes are a special concern for people who use illegal 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.