The goal of this study is to find out how muscle wasting in the mouth and throat affects swallowing (dysphagia) in adults who are critically ill and being treated in intensive care units. The main aims of this research study are to understand: how much and how quickly the oral and suprahyoid muscles waste in critically ill participants, and whether muscle wasting causes problems with swallowing. The investigators will compare critically ill participants with non-critically ill participants to determine if muscle wasting is linked to swallowing problems. In this study, participants will have the size and strength of their mouth and throat muscles measured at four different times during their critical care admission and hospital stay. Tests will also be performed to check how well and how safely participants can swallow. Tongue strength will be measured, and participants will answer questions about their experience with swallowing and eating using patient-reported outcome measures. This study may help identify better ways to diagnose and treat swallowing problems in people who are critically ill, to support safe eating and drinking and promote faster recovery.