This study evaluated respiratory and non-respiratory skeletal muscle ultrasonography as a tool for assessing COPD severity and predicting exacerbations. The study included 240 patients, 120 with stable COPD and 120 with acute exacerbation, with muscle assessment using ultrasound and shear wave elastography. Diaphragmatic and intercostal muscle stiffness was significantly higher during acute exacerbations, supporting ultrasound as a promising repeatable biomarker of COPD severity and recurrent exacerbations.