What Is Septic Shock?

A severe, life-threatening response to an infection

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Septic shock is the most severe level of sepsis, a life-threatening medical emergency that occurs when the immune system has an extreme response to an existing infection.

When this happens, the immune system releases chemicals into the bloodstream that attack the body's own tissues. Blood pressure drops dangerously low, potentially causing organ failure.

This article covers the causes and symptoms of septic shock along with how it's diagnosed and treated. It also includes information about when septic shock is most likely to happen and who is most at risk.

close-up of surgeons hands making an incision in a patient
 Stockbyte / Getty Images

Steps Leading to Septic Shock

Typically, the body responds to an infection by keeping it where it started. But if an infection cannot be contained to that original site, it can spread to other areas of the body via the bloodstream.

Most infections that lead to sepsis and septic shock are caused by bacteria.

When bacteria from one area of the body enters the bloodstream, it is known as bacteremia or septicemia. Unless treated quickly, this can progress into sepsis.

In a typical infection, your immune system releases cytokines to dilate blood vessels at the infection site. This response allows more blood to bring infection-fighting white blood cells to the area.

In sepsis, however, cytokines go into overdrive, creating an overwhelming amount of inflammation throughout the body. This "cytokine storm" damages the heart and its ability to pump blood throughout the body.

Sepsis worsens into septic shock when blood pressure plummets as a result. Blood then stops reaching organs, potentially leading to multiple organ failure.


Sepsis is infection that becomes widespread by traveling through the bloodstream. Septic shock is sepsis at its most severe, when the blood is no longer able to get where it needs to go. Septic shock is life-threatening.

Causes of Septic Shock

Sepsis can start with almost any type of infection, ranging from minor infections like an abscessed tooth or athlete's foot, to serious infections like meningitis, which affects the membranes of the brain and spinal cord.

The infection most commonly begins with one of the following:

Septic shock can also be a complication of fungal infections, such as yeast infection, or viral infections, such as the flu or COVID-19.

You can't pass sepsis along to someone else, but you can spread infections that may lead to sepsis and septic shock.

It is important to remember that not all infections will become sepsis. Even fewer will progress to septic shock.

Infection After Surgery

Sepsis and septic shock are more common after surgery for several reasons. First, urinary tract infections are more common after surgery, and these infections can lead to sepsis.

Second, while an incision made during surgery is obviously needed to allow the surgeon to work, it can also serve as an open door for bacteria or other microorganisms.

Surgery also takes a toll on the body and weakens the immune system. Even if the procedure is minor, there is a risk of infection.

Risk Factors

Infection is the primary risk factor for septic shock, and anyone can get one. That said, the following people are at greater risk:

  • Adults ages 65 or older
  • Children under age 1
  • People who have had sepsis before
  • People with weakened immune systems. They are more likely to contract an infection, which increases their risk of sepsis.

Chronic medical conditions that weaken the immune system, and thus increase your risk of sepsis, include:


Pneumonia, UTIs, and many other infections (even minor ones) can lead to sepsis and septic shock. Those who have surgery are particularly at risk, as are those over 65, under 1, or who have a weakened immune system.


As much as 70% of people who go into septic shock do not survive. Given how quickly sepsis can worsen, approximately 40% of patients with septic shock die even with treatment.

Your chances of survival improve significantly when you get medical attention within the first six hours after you notice symptoms of sepsis, which is why knowing what they are is so important.

Symptoms of sepsis and septic shock can include:

  • Confusion or disorientation
  • Intense pain or discomfort
  • Fever, shivering, or feeling very cold
  • Shortness of breath
  • Clammy or sweaty skin
  • Fast heart rate

If you have any signs or symptoms of sepsis or septic shock, especially if you have a known infection, seek immediate medical attention.

Likewise, if you recently had surgery, closely monitor your incision for signs of infection including pus, redness, or swelling. Go directly to the hospital if you develop a fever or painful urination.

While rare, it is worth noting that septic shock can attack the young and the healthy. It is not uncommon for someone to seem completely well and normal one day and be incredibly sick with septic shock 48 hours later.


There are physical changes that a healthcare provider can check for to help diagnose septic shock. These include:

  • Fever, a body temperature above 100.4 degrees F
  • Hypothermia, a body temperature below 96.8 degrees F
  • Low blood pressure
  • High heart rate
  • Difficulty breathing

In addition, your healthcare provider may run blood and urine tests to check for signs of infection and determine the type. Certain tests can reveal whether or not your organs are functioning as they should.

A critical tool for diagnosing sepsis in its earliest stages is the procalcitonin (PCT) blood test. PCT is a protein that rapidly increases in the blood as a bacterial infection spreads. Doctors can use the PCT test to see how widespread an infection is.

The PCT test is also important because it shows doctors whether or not antibacterial drugs are an appropriate treatment. While bacterial infections cause high PCT results, viral and fungal infections cause a very low PCT count.

You may also need imaging tests, such as X-rays or computed tomography (CT scans), especially if the source of infection is unclear.


If you notice signs of sepsis and septic shock, call 911 right away, especially if you recently had surgery or have a known infection. At the hospital, expect doctors to run urine and blood tests.


Treatment takes place in a hospital. You may be admitted to the intensive care unit (ICU).

Antibiotics should be given within one hour of your arrival at the hospital. Diagnostic tests will be ordered to confirm an infection and its type, but results can take at least 48 hours to come back. The pros of immediate treatment far outweigh any risks.

Antibiotic medications are administered directly into the vein (intravenously) so that they enter the bloodstream immediately. A 2019 survey on antibiotic use in sepsis found that intravenous antibiotics are most commonly given for a duration of seven to 10 days.

If diagnostic tests come back showing a different kind of infection, however, you may be switched from an antibiotics to antifungals, antivirals, or other targeted treatments as appropriate.

Regardless of infection type, you will be given IV fluids to prevent blood pressure from dropping. You may also be given vasopressor medications, which tighten blood vessels to help raise blood pressure.

Should you have difficulty breathing, you may be placed on a ventilator, also known as a respirator or breathing machine.

When Surgery May Be Needed

Surgery may also be recommended after initial antibiotic treatment to remove tissue or amputate a limb damaged by sepsis. Surgery ensures any damaged tissues are gone and you are infection-free. It also helps you maintain as much mobility as possible.

The thought of even potentially losing a limb is startling. It may help to know that only an estimated 1% of sepsis survivors need to have one or more surgical amputations. These typically happen within the first 36 hours to 90 days after sepsis begins.


Immediate sepsis treatment is needed to prevent or minimize complications, including progression to septic shock. Antibiotics are given even before the cause of an infection is confirmed. Fluids and medications are used to keep blood pressure up. Breathing assistance and surgery may be needed in some cases.


Sepsis happens when an infection spreads through the bloodstream to multiple areas in the body. This worsens into septic shock when blood pressure drops dangerously low and impairs organ function.

Septic shock is life-threatening. You must go to the ER immediately if you notice any signs of sepsis. You may be placed in the ICU, and your blood pressure and breathing will be closely monitored.

The medication you are given will depend on the type of infection you have—viral, bacterial, or fungal.

A Word From Verywell

If you or a loved one is a survivor of septic shock, you may want to join a support group or otherwise connect with others who have battled sepsis or any ongoing health issues related to septic shock.

Resources to help you cope in your recovery are also available through the nationwide organization Sepsis Alliance.

9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. What is sepsis?.

  2. Chaudhry H, Zhou J, Zhong Y, et al. Role of cytokines as a double-edged sword in sepsisIn Vivo.

  3. Centers for Disease Control and Prevention. How is sepsis diagnosed and treated?.

  4. Daviaud F, Grimaldi D, Dechartres A, et al. Timing and causes of death in septic shockAnn Intensive Care. 2015 Jun;5(1):16. doi:10.1186/s13613-015-0058-8

  5. Gauer R. Early recognition and management of sepsis in adults: The first six hours. Am Fam Phys.

  6. Cleveland Clinic. Sepsis.

  7. Lee H. Procalcitonin as a biomarker of infectious diseasesKorean J Intern Med. 2013 May;28(3):285-291. doi:10.3904/kjim.2013.28.3.285

  8. Escavo. Results of Escavo's survey on antibiotic use in sepsis.

  9. Reitz K, Kennedy J, Gershengorn HB, et al. Epidemiology of surgical amputation after sepsis. ATSJ. 2019 May;199(1):A7153. doi:10.1164/ajrccm-conference.2019.199.1_MeetingAbstracts.A7153

By Jennifer Whitlock, RN, MSN, FN
Jennifer Whitlock, RN, MSN, FNP-C, is a board-certified family nurse practitioner. She has experience in primary care and hospital medicine.