Cardiovascular diseases Cardiovascular diseases are numerous and occur in different ways. Some of them, such as rheumatism or myocarditis, are primarily heart diseases. Other diseases, such as atherosclerosis or phlebitis mainly affect the arteries and veins. Finally, in the third group of diseases, the cardiovascular system is affected as a whole. The latter group of diseases is related, primarily, to hypertension. Although it is often almost impossible to draw a clear line between heart and veins diseases. For instance, atherosclerosis is a disease of arteries. However, when it develops at the coronary arteries, atherosclerosis is called the coronary artery disease and already applies to heart diseases. Attention: not all of the diseases, which we are accustomed to consider as the heart and blood vessels diseases, are those in fact. For example, heart failure is not a disease but a series of symptoms that may accompany various diseases, even not only those of cardiovascular origin. For example, stenocardia, called also angina pectoris is not an independent disease but a symptom of coronary heart disease.