The underpinning of chronic venous insufficiency (CVI) is valvular dysfunction, which manifests on a spectrum depending on the severity of insufficiency and duration of the disease. In older adults, special consideration must be taken during the patient encounter to account for age-related factors. In this chapter, we discuss the clinical presentation, diagnosis, and mimics of CVI, with a focus on older adults. The epidemiology, risk factors, disease burden, and grave complications—such as thrombosis and ulceration—are reviewed. The physiological impacts of CVI are described, providing the background for treatment strategies, including noninvasive, medical, and surgical therapies.