[1] As the disease worsens, shortness of breath, feeling tired, and swelling of the legs may occur, due to the onset of heart failure.

[2] As of 2013, cardiomyopathies are defined as "disorders characterized by morphologically and functionally abnormal myocardium in the absence of any other disease that is sufficient, by itself, to cause the observed phenotype.

[4] Dilated cardiomyopathy may also result from alcohol, heavy metals, coronary artery disease, cocaine use, and viral infections.

[12] Genetic cardiomyopathies usually are caused by sarcomere or cytoskeletal diseases, neuromuscular disorders, inborn errors of metabolism, malformation syndromes and sometimes are unidentified.

[18] Alcoholism, for example, has been identified as a cause of dilated cardiomyopathy, as has drug toxicity, and certain infections (including Hepatitis C).

[20][23] A more clinical categorization of cardiomyopathy as 'hypertrophied', 'dilated', or 'restrictive',[24] has become difficult to maintain because some of the conditions could fulfill more than one of those three categories at any particular stage of their development.

While in Children, Neuromuscular diseases such as Becker muscular dystrophy, including X-linked genetic disorder, are directly linked with their Cardiomyopathies.

The goal of treatment is often symptom relief, and some patients may eventually require a heart transplant.

[29] Acoramidis (Attruby) was approved for medical use in the United States in November 2024, to treat adults with cardiomyopathy of wild-type or variant (hereditary) transthyretin-mediated amyloidosis (ATTR-CM) to reduce death and hospitalization related to heart problems.