Septic shock is a serious condition that occurs when a body-wide infection leads to dangerously low blood pressure.
Septic shock occurs most often in the very old and the very young. It may also occur in people with weakened immune systems.
Any type of bacteria can cause septic shock. Fungi and (rarely) viruses may also cause the condition. Toxins released by the bacteria or fungi may cause tissue damage. This may lead to low blood pressure and poor organ function. Some researchers think that blood clots in small arteries cause the lack of blood flow and poor organ function.
The body has a strong inflammatory response to the toxins that may contribute to organ damage.
Risk factors for septic shock include:
- Diseases of the genitourinary system, biliary system, or intestinal system
- Diseases that weaken the immune system, such as AIDS
- Indwelling catheters (those that remain in place for extended periods, especially intravenous lines and urinary catheters, and plastic and metal stents used for drainage)
- Long-term use of antibiotics
- Recent infection
- Recent surgery or medical procedure
- Recent or current use of steroid medicines
- Solid organ or bone marrow transplantation
Septic shock can affect any part of the body, including the heart, brain, kidneys, liver, and intestines. Symptoms may include:
Exams and Tests
Blood tests may be done to check for:
- Infection around the body
- Complete blood count (CBC) and blood chemistry
- Presence of bacteria or other organisms
- Low blood oxygen level
- Disturbances in the body's acid-base balance
- Poor organ function or organ failure
Other tests may include:
- A chest x-ray to look for pneumonia or fluid in the lungs (pulmonary edema)
- A urine sample to look for infection
Additional studies, such as blood cultures, may not become positive for several days after the blood has been taken, or for several days after the shock has developed.
Septic shock is a medical emergency. In most cases, people are admitted to the intensive care unit of the hospital.
Treatment may include:
- Breathing machine (mechanical ventilation)
- Drugs to treat low blood pressure, infection, or blood clotting
- High volume of fluids given directly into a vein (intravenously)
- Surgery to drain infected areas, if needed
- Antibiotics or other agents to treat viral or fungal infections
The pressure in the heart and lungs may be checked. This is called hemodynamic monitoring. This can only be done with special equipment and intensive care nursing.
Septic shock has a high death rate. The death rate depends on the person's age and overall health, the cause of the infection, how many organs have failed, and how quickly and aggressively medical therapy is started.
Respiratory failure, cardiac failure, or any other organ failure can occur. Gangrene may occur, possibly leading to amputation.
When to Contact a Medical Professional
Go directly to an emergency department if you develop symptoms of septic shock.
Prompt treatment of bacterial infections is helpful. Vaccination could help prevent some infections. However, many cases of septic shock cannot be prevented.
Bacteremic shock; Endotoxic shock; Septicemic shock; Warm shock
Russell JA. Shock syndromes related to sepsis. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 100.
van der Poll T, Wiersinga WJ. Sepsis and septic shock. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 73.
Review Date 12/6/2021
Updated by: Denis Hadjiliadis, MD, MHS, Paul F. Harron Jr. Associate Professor of Medicine, Pulmonary, Allergy, and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.