Neuraxial anesthesia represents one of the most important advances in anesthesiology, providing safe, reliable alternatives to general anesthesia for a wide range of surgical and obstetric procedures. These anesthetic techniques allow profound sensory, motor, and sympathetic blockade with significant implications for perioperative physiology. Spinal anesthesia delivers a rapid-onset dense blockade, epidural anesthesia provides flexible and titratable anesthesia or analgesia, and combined spinal-epidural techniques harness the strengths of both. The benefits of neuraxial anesthesia extend beyond surgical anesthesia, offering postoperative analgesia, improved pulmonary outcomes, reduced thromboembolic risk, and enhanced recovery after surgery. However, neuraxial anesthesia is not without risks. Sympathectomy-induced hypotension is a predictable physiologic effect, typically becoming clinically significant when block height reaches T4–T6 level, and more serious complications include post-dural puncture headache, local anesthetic systemic toxicity, nerve injury, hematoma, and infection. Contraindications, especially anticoagulation and antiplatelet therapy, must be carefully managed, guided by the most recent 2025 American Society of Regional Anesthesia and Pain Medicine guidelines. This chapter provides a general review of the principles, indications, contraindications, risks, complications, and clinical applications of spinal, epidural, and combined techniques. Emphasis is placed on patient selection, dermatomal considerations, baricity of local anesthetics, neuraxial adjuncts, catheter management, and safety standards. For internists, familiarity with neuraxial anesthesia clarifies its role in perioperative care, informs consultative recommendations, and highlights scenarios where interdisciplinary collaboration is essential.