Peripheral arterial disease (PAD) is characterized by occlusions or stenoses of the lower extremity arteries. Symptoms include intermittent claudication, ischemic rest pain, skin ulceration, and gangrene. Evaluation involves physical exam of leg pulses and imaging tests like CTA or MRA. Treatment options include medical management, endovascular procedures like angioplasty and stenting, and surgical interventions like bypass surgery or amputation. Acute arterial occlusion can be caused by thrombosis, embolism, trauma, or aneurysm and requires urgent treatments like embolectomy or thrombolytic therapy to prevent limb loss and systemic complications.