| Anemia |
| Autonomic dysfunction |
| Cancer-related symptoms including pain, psychological symptoms (anxiety, depression), dyspnea, nausea, anorexia/cachexia, and insomnia |
| Cancer treatment-related (cytotoxic therapy, radiotherapy, bioimmunotherapy) |
| Comorbidities (renal, hepatic, cardiac) |
| Deconditioning |
| Dehydration |
| Hypoxia |
| Infection |
| Mood disorders |
| Neuroendocrine alterations (eg, testosterone deficiency in advanced cancer, hypothyroidism due to immunotherapy) |
| Polypharmacy |
| Tumor byproducts, inflammatory cytokines |
