Sepsis is a clinical syndrome of life-threatening organ dysfunction caused by a dysregulated host response to infection. Septic shock is defined as sepsis with persistent hypotension requiring vasopressors to maintain mean arterial pressure ≥ 65 mm Hg and having a serum lactate > 2 mmol/L, despite adequate volume resuscitation. In septic shock, there is critical reduction in tissue perfusion that can result in acute failure of multiple organs, including the lungs, kidneys, and liver. Common causes in immunocompetent patients include many different species of gram-positive and gram-negative bacteria. Immunocompromised patients may have uncommon bacterial or fungal species as a cause. Signs include fever, hypotension, oliguria, and confusion. Diagnosis is primarily clinical combined with culture results showing infection; early recognition and treatment are critical. Treatment is aggressive fluid resuscitation, antibiotics, pressors, and surgical excision of infected or necrotic tissue and drainage of infectious fluids abscesses if possible.