Geriatric diseases, or conditions common in older adults, include chronic issues like heart disease, diabetes, arthritis, dementia, osteoporosis, cancer, and COPD, alongside "geriatric syndromes" such as falls, delirium, incontinence, and frailty, often involving multiple conditions at once (multimorbidity). Vision/hearing loss, depression, and poor oral health are also prevalent, impacting quality of life and requiring tailored management focusing on prevention, screenings, and managing chronic symptoms.