Sepsis should be treated as an emergency in the same way as heart attacks, a watchdog has said.
The National Institute for Health and Care Excellence (Nice), said doctors and nurses should treat people who show signs of sepsis with the same urgency as those who say they have chest pain.
Sepsis is a life-threatening condition that occurs when the body's immune system goes into overdrive as it tries to fight an infection. It is often called septicaemia or blood poisoning.
According to the UK Sepsis Trust, there are around 150,000 cases of sepsis in the UK each year and 44,000 deaths.
In its new guidance, Nice called for health professionals to think about the possibility of sepsis in all patients who may have an infection.
GPs should send any patient who might have sepsis to hospital in an ambulance. Once in hospital they should be seen by a senior doctor or nurse immediately who can start treatment.
The guidance also includes a checklist of signs and symptoms and details on what to do next.
The move has been welcomed by Melissa Mead, whose son William died from sepsis following a string of NHS failings.
In January, a report into the death of the 12-month-old criticised GPs, out-of-hours services and a 111 call handler who failed to spot he had sepsis caused by an underlying chest infection and pneumonia.
Mrs Mead said she was "delighted" with the new guidance, adding: "This could not come any sooner. Sadly, we have been touched in very real terms by sepsis and could not agree more that clinicians need to start asking 'Could this be sepsis?'.
"The awareness of sepsis amongst health professionals and the public is severely lacking, so joined -up thinking and action is necessary to drive down the number of fatalities from sepsis. After all, if I had been aware of it, and those clinicians that treated William were 'thinking sepsis' he would more than likely be alive today."
Early symptoms of sepsis include fast breathing or a fast heartbeat, high or low temperature, chills and shivering, and people may or may not have a fever.
Severe symptoms can develop soon after, and include blood pressure falling low, dizziness, disorientation, slurred speech, mottled skin, nausea and vomiting.
Without prompt treatment with antibiotics, sepsis can lead to multiple organ failure and death.
Professor Saul Faust, from the University of Southampton and chairman of the group that developed the Nice guideline, said: "Anyone can succumb to sepsis.
"Sepsis can be difficult to diagnose with certainty. We want clinicians to start asking 'could this be sepsis?' much earlier on so they can rule it out or get people the treatment they need. The thinking should be similar to considering that chest pain could be heart-related.
"Just like most people with chest pain are not having a heart attack, the majority of people with an infection will not have sepsis. But if it isn't considered then the diagnosis can be missed."
A report by the National Confidential Enquiry into Patient Outcome and Death published last year found delays in identifying sepsis in over a third (36%) of cases.
Dr Ron Daniels, chief executive of the UK Sepsis Trust, said: "Sepsis is a condition whose time has come. We must act decisively to save many of the thousands of lives claimed every year."
Dr Maureen Baker, chairwoman of the Royal College of GPs, said: "The diagnosis of sepsis is a huge worry for GPs as initial symptoms can be similar to common viral illnesses, so we welcome any guidance or support to help us identify it as early as possible.
"Sepsis is one of the College's Spotlight projects until April 2017, and as part of this programme we will be working with NHS England and Health Education England to help improve the outcomes from sepsis, particularly in collaboration with colleagues across the NHS to reduce deaths from sepsis each year across the UK."