Shahida Begum, 39, visited Newham University Hospital in London after noticing a red rash and pain in her right side with sickness, dizziness and coughing.
The mum-of-two was diagnosed with a muscle sprain and given medication - but died the following day from multiple organ failure after suffering three cardiac arrests.
The inquest concluded that if Shahida had been sent to A&E following her screening assessment "it is likely her death would have been avoided."
Mohammed Rahman, Shahida's husband of ten years, said the family has been "shocked and devastated" by her sudden death.
The family-of-four, from Ilford, London, were enjoying their first year in a new, refurbished home where they hoped to create "a lifetime of memories".
Speaking after the inquest, IT manager, Mohammed, 47, said: "Throughout the whole period that Shahida was ill, we had been in contact with a number of healthcare professionals, all of whom reassured us that it was not life threatening and that she would pull through.
"Even when she was admitted to A&E, I knew it was serious but I did not think we would lose her.
"It seemed to happen so suddenly and I did not have time to come to terms with what had happened.
"It is still difficult to think that my wife and the mother of my children would still be alive if her symptoms had been diagnosed sooner.
"We miss Shahida every day and it is heart-breaking to know that she is no longer with us and will not get to see her children grow up
"All we can hope for now is that lessons are learned and that measures are put in place to ensure that this does not happen to any other families.
"We wouldn't wish this pain on anyone else."
Shahida, a nursery nurse, was directed towards the GP service - run by Newham GP Co-operative - where Mohammed took her the following day.
Her condition was deteriorating rapidly and she collapsed and was taken back to Newham University Hospital by ambulance and diagnosed with sepsis.
Senior coroner Nadia Persaud will issue a Prevention of Future Deaths order instructing Newham GP Co-operative and Barts Health NHS Trust, which runs the hospital, to tell her what steps they will take to improve the screening service which decides whether patients are referred to GPs or A&E.
An internal investigation by Barts Health NHS Trust also highlighted a range of issues.
A report found the 'root causes' for Shahida's death was that she was incorrectly sent to the GP area, a diagnosis of a muscle sprain did not fit with all of her symptoms, sepsis was not considered and National Institute for Health and Care Excellence guidelines for assessing the risk of sepsis were not followed.
Alexandra Winch, specialist medical negligence lawyer at Irwin Mitchell representing the family, said: "Understandably Shahida's sudden death has a profound effect on her family who are still struggling to come to terms with what happened.
"The family have had a number of concerns about what happened in the lead up to her death and sadly the inquest and NHS investigation has identified a number of worrying areas in the care Shahida received.
"While nothing can make up for Shahida's death we recognise the recommendations that the Hospital Trust has included in its report. It is now vital that these are implemented so staff across all departments are aware of the signs of sepsis and how early detection is key to beating it."
Shahida and Mohammed married in 2009 and had two children, Maryam, six and three-year-old Amaan.
Shahida returned home from work on Tuesday, July 3, last year complaining of feeling unwell.
Over the coming days her symptoms persisted and she developed a rash under her right arm.
She attended an out of hours GP appointment on Friday, July 6, but was reassured that her symptoms were nothing to be concerned about.
But her condition continued to deteriorate over the weekend and on Monday, July 9, Mohammed took her to hospital where - following an initial 'screening assessment' - she was directed to the GP service and prescribed pain killers.
She returned to the hospital on July 10 and she was diagnosed with sepsis.
Shahida was given antibiotics, fluid resuscitation and medication to boost her blood pressure while fluid was also identified on a CT scan.
A decision was made to drain the fluid but she died just after 6pm on July 10 during preparations for the procedure.
The report by Barts NHS Trust made 12 recommendations.
These included annual sepsis awareness training for all clinical staff working in the urgent care centre, sepsis screening guidelines to be available for staff, a leaflet which can be given to patients at risk of developing the infection on discharge to be developed and 'key learning points' to be shared with all staff working in the GP area and emergency department.