What clinical condition does "Asthenia" refer to?

Asthenia specifically refers to muscle weakness, which distinguishes it from other similar conditions like general fatigue or lack of energy. It is a term often used in a clinical context to describe a state where a person experiences reduced strength or strength deficits in their muscles, making it difficult to perform everyday activities. While extreme fatigue and lack of energy can be associated with asthenia, they are broader symptoms and do not pinpoint the specific issue of muscular weakness. Painful muscles relate more to conditions like myalgia and are not synonymous with asthenia. Therefore, the focus on muscle weakness makes this the most accurate definition of the clinical condition referred to as "Asthenia."