Fig. 1. CAD in cancer patients is characterized by dysfunction of the autonomic nervous system and the cardiovascular system due to various causes, leading to resting tachycardia, orthostatic hypotension, and decreased HRV and survival. CAD has four etiologies: 1) cancer itself, 2) cancer treatments, 3) lifestyle changes due to cancer, and 4) preexisting comorbidities. Although CAD caused by cancer itself and CAD caused by cancer treatment have distinct underlying mechanisms, the main common mechanisms are inflammatory cytokine-mediated oxidative stress, mitochondrial dysfunction, microvascular damage, and neuronal dysfunction. Cancer-induced lifestyle changes such as decreased physical activity, weakness, sudden weight gain, edema, emotional stress, and insomnia all contribute to CAD, and so these factors need to be managed. Other comorbidities besides cancer can also cause and worsen CAD, and also need to be treated. ANS, autonomic nervous system; CAD, cardiovascular autonomic dysfunction; CATR, CATR tumerogenic conversion 1 protein; DM, diabetes mellitus; HRV, heart-rate variability; IL, interleukin; RAAS, renin-angiotensin-aldosterone system; RNS, reactive nitrogen species; ROS, reactive oxygen species; TNF, tumor necrosis factor.