Cause of death for Missouri girl, 8, who died mid-flight while on vacation with her family is revealed

An eight-year-old Missouri girl died from multiple health complications as she was flying with her family on vacation.

Elementary schooler Sydney Weston was on her way to Chicago with her family when she became ill and then unresponsive after taking off from Joplin, Missouri, on a SkyWest flight in June.

The flight was diverted to Peoria, Illinois, about 45 minutes after take off and forced to make an emergency landing.

Sydney was then declared dead at the hospital, with the medical examiner now saying it was due to chronic primary adrenalitis - a chronic condition in which your adrenal glands don't produce enough of the hormones cortisol and aldosterone.

Sydney Weston was on her way to Chicago with her family when she became ill and then unresponsive after taking off from Joplin, Missouri, on a SkyWest flight in June

She also had multiple infections which included strep and enterovirus as well  as duodenitis- an inflammation in the small intestine - and thyroiditis, an inflammation of the thyroid grand. 

Peoria County Coroner Jamie Harwood said the conditions suggest an underlying autoimmune disorder, as reported by 25News Now. 

Sydney, from Carl Junction, Missouri, was traveling with her her parents Whitney and Dan and her older brother Evan.

The Peoria County Sheriff's Office said: 'When the plane landed Deputies, AMT Personnel, and Air National Guard Fire personnel immediately received the 8-year-old female child and began life-saving measures.

The flight was operated by SkyWest, which functions through partnerships with United, Delta Air Lines, American Airlines and Alaska Airlines

'The child was transported to a local hospital by AMT where she was unfortunately pronounced deceased.

'Please keep the child's family and everyone who was involved in this traumatic experience in your thoughts and prayers.'

The flight was operated by SkyWest, which functions through partnerships with United, Delta Air Lines, American Airlines and Alaska Airlines.

A SkyWest spokesperson said: 'We appreciate the efforts of our crewmembers who responded quickly to assist and the medical personnel who met the aircraft.'