What is Septic Shock?


Have you ever wondered what septic shock is or if it could affect you? This potentially fatal condition arises when an infection spreads throughout the body and triggers an inflammatory response. While it's a rare occurrence, septic shock requires prompt medical treatment to ensure the best possible outcome. Being aware of the symptoms and risk factors can help you protect yourself and your loved ones.1

However, what precisely is a septic shock?

Septic shock is a complication of sepsis and is a consequence of a host response to infection that triggers an inflammatory reaction in the body. It is distinguished by alterations in the cells’ metabolism, blood circulation, and persistent hypotension or low blood pressure and demands immediate medical attention since it may be fatal.2,3,4

Although exact numbers are difficult to determine, according to the latest information, the World Health Organisation (WHO) estimates that 11 million people died from sepsis in 2017, accounting for about 20% of all deaths globally. Children, especially those under 5 years old, the elderly, those with weakened immune systems, those with chronic conditions like diabetes, and pregnant individuals are those who are most affected. The vast majority of septic shocks, as well as the deaths due to them, come from low-income countries, even though the vast majority of studies on this disease originate from high-income countries.5

Causes of septic shock

A septic shock can occur as a result of any infection, wherever in the body, that is primarily caused by bacteria, though it can also be caused by fungi, such as candida, or by a virus.

The most common causes of septic shock are either endotoxins produced by Gram-negative bacteria such as Escherichia coli or bacterial infections contracted in a hospital setting, typically Gram-positive bacteria like group B Streptococcus. Another example of a Gram-positive bacteria is Methicillin-resistant Staphylococcus aureus (MRSA), which is resistant to many antibiotics and has become more and more widespread in recent years.1,6,7 According to the World Health Organisation (WHO) global report on sepsis epidemiology and burden, these microorganisms were mainly responsible for respiratory tract infections and diarrhoeal diseases.5

The main complication of sepsis is nothing less than the immune system's reaction to the infection. Pro-inflammatory cytokines are typically generated in sepsis to defend our bodies against pathogens in the early stages of infection. Sometimes the immune system produces too many cytokines or does not turn them off when the infection is under control. This extremely inflammatory process can result in an anti-inflammatory reaction to control the inflammatory response to the invading microorganism, which can destabilise a person's immune system. When this hyperinflammatory process occurs, it may harm organs in the body that are not infected. In the end, it causes a variety of organs to become dysfunctional due to the lack of blood and oxygen, due to hypotension, vascular damage, clotting events, or in other words, a septic shock.1,4

Signs and symptoms of septic shock

Since several of the symptoms that define septic shock may also be present in other disorders, caution must be exercised while attempting to identify the condition. The following are possible symptoms and indicators of septic shock:1,2

  • Hypotension, also called low blood pressure that is resistant to fluid resuscitation
  • Tachycardia or rapid heartbeat with more than 90 beats per minute
  • Tachypnoea or rapid breathing greater than 20 breaths per minute
  •  Fever greater than 38 °C or hypothermia less than 36 °C
  •  Shivers or shakes
  •  Confusion or lethargy
  •  Pale and cyanotic extremities
  • Other signs more specific to the organs involved such as little to no urine production

In the early stages of septic shock, it can be called "hot shock" when the blood pressure is still maintained despite the presence of other symptoms. On the other hand, the “cold shock” happens in a later stage of the septic shock, when the immune system is already dysregulated and there is hypotension. It might be accompanied by cold extremities and a lack of capillary refilling.1,2

Management and treatment for septic shock

Septic shock is a complication of sepsis that occurs when the immune system is out of homeostasis or balance. If not treated promptly, septic shock can cause organ damage as well as in more extreme cases death. To avoid such dangerous scenarios, responsible doctors provide antimicrobial medications focused on the pathogenic organisms responsible for the infection. Moreover, fluid replacement is crucial, whether it be with blood-derived colloid fluids like albumin or crystalloid fluids.2,8

To enhance the patient's response, doctors may provide vasoactive substances such as vasopressin, corticosteroids, and norepinephrine for warm shock or epinephrine for cold shock. Surgical intervention might also be required to remove the tissues in situations where they have been severely damaged or necrosed.2


Early recognition of symptoms and proper diagnosis of septic shock is paramount to reduce the risk and impact of this condition on patients.

There is no single test that can diagnose septic shock on its own because the condition can be a very complex sickness that can manifest in any place of the body and with many types of germs. Therefore, physicians may request some exams and certain blood tests, such as:1,2

  • Blood pressure
  • Heart rate
  • Oxygen monitoring
  • Glucose
  • Complete blood count with differential counts
  • Procalcitonin
  • C-reactive protein (CRP)
  • INR and partial thromboplastin time
  • Venous oxygen saturation
  • PaO2
  • Electrolyte panel
  • Bilirubin and creatinine
  • Lactate

Moreover, it is very important when there is sepsis or septic shock to know which microorganism is responsible for the infection, as well as the most appropriate antimicrobial therapies. To do that doctors may ask for two sets of blood cultures or cultures of other potential places of infection. Some other radiological tests that can be very useful are X-ray and CT scans.1

Risk factors

Some patients need to take extra precautions when they get infections, especially if they are already undergoing sepsis, because they may also have additional health concerns that are thought to be contributing factors to their infection, such as:1,9

  • Diabetes
  • Kidney disease
  • Liver cirrhosis
  • Neonates
  • Elderly people over 65 years of age
  • Being pregnant
  • Using recreational drugs
  • Having artificial joints or heart valves
  • Hospitalized people in intensive unit care (ICU)
  • People with no spleen

Having a compromised immune system is also considered a risk factor. In this situation are people who are receiving treatments for cancer or with diseases such as HIV and AIDS, or other immunological diseases.1,9


It is important to treat septic shock as soon as possible as it can be fatal if not treated promptly. Despite the fact that it can be treated at an early stage, there are still some complications that may arise from it. As a result of this condition, there are many complications, such as organ failure, such as respiratory failure, or cardiovascular failure. If the condition is more severe, it can affect not only one organ but also several simultaneously, also referred to as multiple organ failure. It is also important to note that there are other complications as well:4

  • Acute respiratory distress syndrome (ARDS)
  • Blood clots or disseminated intravascular coagulation (DIC)
  • Amputation or removal of necrotized and gangrenous tissues


How can I prevent septic shock?

According to the WHO, there are two ways to prevent septic shock. The first is to use measures to prevent the transmission of infection-causing microorganisms by:

  • Hygiene measures, such as frequent hand washing
  • Having access to sanitation and clean water
  • Up-to-date vaccinations
  • Maintaining a balanced diet

In addition, one can try to prevent septic shock, avoiding the infection turns into sepsis, by medical follow-up and timely diagnosis.

How common is septic shock?

Septic shock is a very common medical condition, with an estimated 48.9 million cases and 20% of deaths worldwide in 2017, according to the latest WHO report.

When should I see a doctor?

Septic shock is a potentially fatal condition, so when you experience fever, hypotension, lethargy, shivers, pale or cyanotic extremities you should seek medical help.


Septic shock is a very serious and potentially fatal condition that can develop as a result of sepsis, which is a condition where the body’s immune system overly responds to an infection. Normally, when you have an infection, your immune system produces substances called cytokines that help fight off the invading germs. However, sometimes the immune system produces too many cytokines or does not turn them off when the infection is under control. This leads to widespread inflammation in the body, which can harm your organs and tissues by reducing their blood supply and oxygen levels. This is called sepsis and it can affect any organ system in the body. 

Septic shock is a more severe form of sepsis that happens when the inflammation also causes your blood pressure to drop dangerously low. This means that your organs do not receive enough blood and oxygen to function properly, and they may start to fail. This can affect your heart, lungs, kidneys, liver, brain, and other vital organs. If septic shock is not treated quickly and effectively, it can cause irreversible damage to your organs and lead to death. Septic shock is a medical emergency that requires immediate attention and medical care.


  1. Mahapatra S, Heffner AC. Septic Shock. In: StatPearls. Treasure Island (FL): StatPearls Publishing; 2023. Available from: http://www.ncbi.nlm.nih.gov/books/NBK430939/
  2. Singer M, Deutschman CS, Seymour CW, Shankar-Hari M, Annane D, Bauer M, et al. The Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3). JAMA. 2016 Feb 23;315(8):801–10. Available from: https://doi.org/10.1001/jama.2016.0287
  3. Dellinger RP, Levy MM, Rhodes A, Annane D, Gerlach H, Opal SM, et al. Surviving Sepsis Campaign: International Guidelines for Management of Severe Sepsis and Septic Shock: 2012. Critical Care Medicine. 2013 Feb;41(2):580. Available from: https://journals.lww.com/ccmjournal/Fulltext/2013/02000/Surviving_Sepsis_Campaign__International.24.aspx
  4. Beltrán-García J, Osca-Verdegal R, Jávega B, Herrera G, O’Connor JE, García-López E, et al. Characterization of Early Peripheral Immune Responses in Patients with Sepsis and Septic Shock. Biomedicines. 2022 Mar;10(3):525. Available from: https://www.mdpi.com/2227-9059/10/3/525
  5. Rudd KE, Johnson SC, Agesa KM, Shackelford KA, Tsoi D, Kievlan DR, et al. Global, regional, and national sepsis incidence and mortality, 1990–2017: analysis for the Global Burden of Disease Study. The Lancet. 2020 Jan 18;395(10219):200–11. Available from: https://www.thelancet.com/article/S0140-6736(19)32989-7/fulltext
  6. Lam SW, Bauer SR, Neuner EA. Predictors of septic shock in patients with methicillin-resistant Staphylococcus aureus bacteremia. International Journal of Infectious Diseases. 2012 Jun 1;16(6):e453–6. Available from: https://www.ijidonline.com/article/S1201-9712(12)00065-3/fulltext
  7. Stoll BJ, Hansen NI, Sánchez PJ, Faix RG, Poindexter BB, Van Meurs KP, et al. Early Onset Neonatal Sepsis: The Burden of Group B Streptococcal and E. coli Disease Continues. Pediatrics. 2011 May;127(5):817–26. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3081183/
  8. Labib A. Sepsis Care Pathway 2019. Qatar Med J. 2019 Nov 7;2019(2):4. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6851952/
  9. Gotts JE, Matthay MA. Sepsis: pathophysiology and clinical management. BMJ. 2016 May 23;353:i1585. Available from: https://www.bmj.com/content/353/bmj.I1585
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Inês Dias

Master's Degree, Molecular Biology and Genetics, Faculty of Sciences, University of Lisbon

Inês is a scientist in the field of Biomedical Sciences, with a wealth of experience in various laboratory procedures. Her expertise is evident in her work as clinical analysis technician, performing puncture procedures for the collection of biological samples. She has also played a key role in COVID-19 sample processing in a laboratory setting. Recently obtained her master’s in Molecular Biology and Genetics from the Faculty of Sciences at the University of Lisbon.

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