When you have sepsis, chemicals released by your body’s defence mechanism trigger inflammatory responses in their attempt to kill invading microorganisms.

What is sepsis?

Sepsis is the body’s extreme response to an infection. It is a life-threatening medical emergency due to complications arising from an infection. This can happen, for example, when bacteria from an infection enter the bloodstream (septicaemia) and spread throughout the body.

With sepsis, chemicals released by the body to combat these microorganisms trigger inflammatory responses. In severe cases, blood flow to vital organs like the brain, heart or kidneys can be impaired. This in turn can lead to tissue damage, multi-organ failure and even death if not treated quickly enough.

Common causes

Sepsis stems from an infection by bacteria, viruses, fungi or even polymicrobial (various combinations of these microorganisms). Common types of infections that can lead to sepsis include infections in the urinary tract, lung, skin and gastrointestinal tract.

Who is at risk?

How severe an infection becomes and whether it leads to sepsis depends on many factors, including the type, severity and location of the infection, and the age and health condition of the patient.

Anyone can develop sepsis. However, people who are at greater risk of developing more severe infections include those who:
  • Are older (e.g. over 65 years old)
  • Are obese
  • Have chronic medical conditions (e.g. diabetes, lung disease, kidney disease, cancer)
  • Are immunocompromised (e.g. cancer patients  on chemotherapy, non-cancer patients requiring drugs that affect immune system e.g. steroids)
  • Have genetic immunodeficiencies

People who were hospitalised before are also more susceptible to contracting nosocomial infections (healthcare-associated infections) due to their altered human microbiome from staying in the hospital.

When to seek treatment

In general, it is advised to seek medical help for any suspected infection early so that it can be treated before the condition worsens. This is especially so if the patient is elderly, immunocompromised or has existing comorbidities. In such cases, the patient should see a doctor as soon as possible if they are feeling unwell, including when the symptoms are non-specific.


When diagnosed early, infections can be expeditiously treated with appropriate medications (e.g. antibiotics for bacterial infections). More extensive treatments may be required if the condition has progressed. Early assessment and treatment give the best outcome.

Early and advanced symptoms

As sepsis begins with an infection, the early symptoms can be non-specific or may be localised to the site of infection.

Non-specific symptoms include feeling fatigued, having loss of appetite, feeling “warm”. These are signs that an infection may be present within the body. A medical assessment is required to confirm infection or sepsis.

Symptoms of sepsis may be localised to the area of infection. In skin infections, for example, the surrounding skin around the wound may become red, swollen and painful. A urinary tract infection (UTI) can present with frequency or urgency, or pain in passing urine.

If sepsis is left uncontrolled, the patient can experience a worsening of symptoms — an increased heart rate, shortness of breath, confusion or disorientation, fever and cold or clammy skin. At its most severe, the patient may suffer multi-organ failure and septic shock. The mortality rate at this point is often high.

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