Saliva is a vital bodily fluid that facilitates digestion, speech, and swallowing, while also protecting oral tissues through its antimicrobial and lubricating properties. Dry mouth, also known as xerostomia, is typically associated with reduced salivary flow or, in rarer cases, psychological factors. Key causes of decreased salivary flow include dehydration, certain medications, radiation therapy applied to the head and neck region, and specific systemic diseases such as Sjogren’s syndrome. Individuals with salivary gland hypofunction are at a heightened risk for various oral pathologies, making symptomatic treatment and preventive approaches essential. This chapter provides a comprehensive overview of the assessment of dry mouth, alleviation of its symptoms, and preventive measures, based on the latest literature.