General Weakness

Patients use weakness to mean two very different things: reduced muscle power, and the subjective heaviness of fatigue. Separating them changes the whole assessment. True generalised weakness with objective power loss suggests neuromuscular disease, electrolyte disturbance, thyroid disease, or steroid myopathy. Subjective weakness far more often reflects anaemia, infection, depression, sleep disruption, or deconditioning. In older adults, sarcopenia develops silently and is measurable with a sit-to-stand test long before it becomes disabling. Acute generalised weakness developing over hours to days — particularly if it ascends from the legs — is a neurological emergency.

• •Difficulty rising from a chair without using arms
• •Struggling with stairs
• •Dropping objects
• •Heavy limbs unrelated to exertion
• •Reduced grip strength
• •Unintended weight loss

• •Anaemia or iron deficiency
• •Hypothyroidism or thyrotoxicosis
• •Vitamin D deficiency with proximal myopathy
• •Low potassium, sodium or calcium
• •Chronic infection or inflammation
• •Depression
• •Deconditioning after illness
• •Statin or steroid myopathy

Loss of muscle mass and quality (sarcopenia, disuse), impaired oxygen delivery (anaemia), endocrine disturbance (thyroid, adrenal, vitamin D deficiency), electrolyte abnormality, chronic inflammation, and drug effects including statins and corticosteroids.