Asthenia, also known as weakness, is the feeling of body fatigue or tiredness. A person experiencing weakness may not be able to move a certain part of their body properly. Asthenia is best described as a lack of energy to move certain muscles or even all muscles in the body.
Some people experience asthenia in a certain area of their body, such as the arms or legs. Others may experience full-body weakness, which is often the result of a bacterial or viral infection such as influenza or hepatitis.
Weakness may be temporary, but it’s chronic or continuous in some cases.