Asthenia is generalized weakness associated with fatigue and lethargy. It is one of the most common symptoms in patients with advanced cancer, with profound effects on the quality of life.
It is most frequently associated with progression of the cancer, although other causes need to be considered, as some are amenable to treatment or palliation. Asthenia occurs most frequently in patients with advanced disease who have lost a significant amount of weight and muscle mass.
Causes of generalized weakness and asthenia
- Neuromuscular: cachexia-related loss of muscle mass, cachexia-related muscular dysfunction, myasthenic syndrome (Lambert-Eaton), polymyositis, overactivity, prolonged immobility, polyneuropathy (carcinomatous or independent of cancer), intracranial tumor, paraneoplastic encephalopathies, acute confusion, or delirium
- Metabolic: electrolyte imbalance, dehydration, renal (hepatic) failure
- Endocrine: adrenal insufficiency, ectopic ACTH secretion, diabetes
- Malnutrition: inanition, malabsorption
- Psychological: anxiety, depression, dependency, boredom, insomnia
- Anticancer therapy: radiotherapy, chemotherapy, interferon
- Drugs: opioids, tranquilizers, sedatives, antidepressants, diuretics, others
Woodruff R. Palliative medicine evidence-based symptomatic and supportive care for patients with advanced cancer. 4th edition. Oxford University Press, 2004. p. 428.