Sepsis is a potentially life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs.

Sepsis
Skin blotching and inflammation due to sepsis
Pronunciation	/ˈsɛpsɪs/
Specialty	Infectious disease
Symptoms	Fever increased heart rate low blood pressure increased breathing rate low urine output absent or near absent urine output severe pain confusion
Complications	Multiple organ dysfunction syndrome temporary, transient, or permanent organ damage extra corporeal membrane oxygenation blood filtration or dialysis
Usual onset	May be rapid (less than three hours) or prolonged (several days)
Causes	Immune response triggered by an infection
Risk factors	Young or old age cancer diabetes major trauma asthma Chronic Obstructive Pulmonary Disease multiple myeloma burns
Diagnostic method	Systemic inflammatory response syndrome (SIRS), qSOFA
Prevention	influenza vaccination, vaccines, pneumonia vaccination
Treatment	Intravenous fluids, antimicrobials, vasopressors
Prognosis	10 to 80% risk of death; These mortality rates (they are for a range of conditions along a spectrum: sepsis, severe sepsis, and septic shock) may be lower if treated aggressively and early, depending on the organism and disease, the patient's previous health, and the abilities of the treatment location and its staff
Frequency	0.2–3.0 per 1,000 a year (developed world)

This initial stage of sepsis is followed by suppression of the immune system. Common signs and symptoms include fever, increased heart rate, increased breathing rate, and confusion. There may also be symptoms related to a specific infection, such as a cough with pneumonia, or painful urination with a kidney infection. The very young, old, and people with a weakened immune system may have no symptoms of a specific infection, and the body temperature may be low or normal instead of having a fever. Severe sepsis causes poor organ function or blood flow. The presence of low blood pressure, high blood lactate, or low urine output may suggest poor blood flow. Septic shock is low blood pressure due to sepsis that does not improve after fluid replacement.

Sepsis is caused by many organisms including bacteria, viruses and fungi. Common locations for the primary infection include the lungs, brain, urinary tract, skin, and abdominal organs. Risk factors include being very young or old, a weakened immune system from conditions such as cancer or diabetes, major trauma, and burns. Previously, a sepsis diagnosis required the presence of at least two systemic inflammatory response syndrome (SIRS) criteria in the setting of presumed infection. In 2016, a shortened sequential organ failure assessment score (SOFA score), known as the quick SOFA score (qSOFA), replaced the SIRS system of diagnosis. qSOFA criteria for sepsis include at least two of the following three: increased breathing rate, change in the level of consciousness, and low blood pressure. Sepsis guidelines recommend obtaining blood cultures before starting antibiotics; however, the diagnosis does not require the blood to be infected. Medical imaging is helpful when looking for the possible location of the infection. Other potential causes of similar signs and symptoms include anaphylaxis, adrenal insufficiency, low blood volume, heart failure, and pulmonary embolism.

Sepsis requires immediate treatment with intravenous fluids and antimicrobials. Ongoing care often continues in an intensive care unit. If an adequate trial of fluid replacement is not enough to maintain blood pressure, then the use of medications that raise blood pressure becomes necessary. Mechanical ventilation and dialysis may be needed to support the function of the lungs and kidneys, respectively. A central venous catheter and an arterial catheter may be placed for access to the bloodstream and to guide treatment. Other helpful measurements include cardiac output and superior vena cava oxygen saturation. People with sepsis need preventive measures for deep vein thrombosis, stress ulcers, and pressure ulcers unless other conditions prevent such interventions. Some people might benefit from tight control of blood sugar levels with insulin. The use of corticosteroids is controversial, with some reviews finding benefit, and others not.

Disease severity partly determines the outcome. The risk of death from sepsis is as high as 30%, while for severe sepsis it is as high as 50%, and septic shock 80%. Sepsis affected about 49 million people in 2017, with 11 million deaths (1 in 5 deaths worldwide). In the developed world, approximately 0.2 to 3 people per 1000 are affected by sepsis yearly, resulting in about a million cases per year in the United States. Rates of disease have been increasing. Some data indicate that sepsis is more common among males than females, however, other data show a greater prevalence of the disease among women. Descriptions of sepsis date back to the time of Hippocrates.