Swallowing difficulty, or dysphagia, is a common symptom resulting from aging, disease, or stress-related mechanisms (functional dysphagia). Dysphagia affects physical and mental health, quality of life, and social interactions. If left untreated, it can lead to serious complications such as malnutrition, dehydration, and aspiration pneumonia. However, many individuals fail to recognize their condition.

The diagnosis of dysphagia relies on a patient’s medical history, clinical examination, and diagnostic tests such as videofluoroscopy (VFS) or flexible endoscopic evaluation of swallowing (FEES). Because swallowing is a complex process, benign symptoms unrelated to disease can occur. This condition, known as functional dysphagia, is as debilitating and costly as organic dysphagia.

This dissertation aimed to translate and validate the Finnish version of the Eating Assessment Tool (EAT-10) for assessing swallowing symptoms and to evaluate the effectiveness of EAT-10 and the water swallow test (WST) in determining the need for VFS. The Finnish EAT-10 proved to be a valid, reliable tool for diagnosing and monitoring dysphagia. The WST was more effective than EAT-10 in identifying patients who would benefit from VFS. Reliability analyses of VFS assessments revealed the strongest agreements in evaluating pharyngeal residues and penetration-aspiration findings. The clinical significance of objective measurements remained unclear.

This study also examined the impact of FEES with swallowing guidance on dysphagia. The results showed notable benefits, particularly for patients with functional dysphagia, as early as the first month. These findings highlight the importance of early intervention for this group, for whom extensive diagnostic testing may not be necessary.

This research refines dysphagia assessment and diagnostic protocols, introduces the validated Finnish EAT-10 questionnaire, and emphasizes targeted use of diagnostic tools like VFS and FEES. It provides valuable insights to improve patient outcomes, reduce healthcare costs, and optimize resource use in managing dysphagia.