Risk factors

You have an increased risk of a heart murmur if someone in your family had a heart defect associated with the unusual sounds.

Many different medical conditions can increase your risk of heart murmurs, including:

• A weakened heart muscle (cardiomyopathy)
• An infection of the lining of the heart (endocarditis)
• Blood disorders marked by a high number of certain white cells, called eosinophils (hypereosinophilic syndrome)
• Certain autoimmune disorders, including lupus and rheumatoid arthritis
• Chemicals from a rare tumor in the lungs or gastrointestinal system that enter your bloodstream (carcinoid syndrome)
• Heart valve disease
• High blood pressure (hypertension)
• High blood pressure in the lungs (pulmonary hypertension)
• History of rheumatic fever
• Overactive thyroid (hyperthyroidism)

Having uncontrolled diabetes or a rubella infection during pregnancy increases your baby's risk of developing heart defects and a heart murmur. Use of certain medications, alcohol or drugs during pregnancy can lead to heart defects in a developing baby, which may cause a heart murmur.