The cause of dilated cardiomyopathy often isn't known. As many as one-third of the people who have dilated cardiomyopathy inherit it from their parents.
Certain diseases, conditions, and substances also can cause the disease, such as:
- Coronary heart disease, heart attack, high blood pressure, diabetes, thyroid disease, viral hepatitis, and HIV
- Infections, especially viral infections that inflame the heart muscle
- Alcohol, especially if you also have a poor diet
Complications during the last month of pregnancy or within 5 months of birth
- Certain toxins, such as cobalt
- Certain drugs (such as cocaine and amphetamines) and two medicines used to treat cancer (doxorubicin and daunorubicin)
This answer is based on source information from the National Heart, Lung, and Blood Institute.