Asthenia

Asthenia (Greek: ασθένεια, lit. lack of strength but also disease) is a medical term denoting a feeling of weakness without actual loss of strength.

Causes of asthenia
The condition is commonly seen in patients suffering from chronic fatigue syndrome, sleep disorders or chronic disorders of the heart, lungs or kidneys. Differentiating between asthenia and true muscular weakness is often difficult, and in time asthenia in chronic disorders is seen to progress into a primary weakness. Also a condition in which the body lacks or has lost strength either as a whole or in any of its parts. General asthenia occurs in many chronic wasting diseases, such as anemia and cancer, and is probably most marked in diseases of the adrenal gland. Asthenia may be limited to certain organs or systems of organs, as in asthenopia, characterized by ready fatiguability.

Common causes of asthenia
 * Addison's disease
 * Anemia
 * Anxiety
 * Chemotherapy
 * Chronic fatigue syndrome
 * Chronic pain
 * Deconditioning / sedentary lifestyle
 * Dehydration and electrolyte disturbance
 * Depression
 * Diabetes
 * Fibromyalgia
 * Heart disease
 * Hypothyroidism
 * Infections
 * Medications including amiodarone
 * Narcotics
 * Paraneoplastic syndrome
 * Pregnancy/postpartum
 * Pulmonary disease
 * Renal disease
 * Sleep disorders