Rainè Riggs died Saturday, the day Sanders returned to Vermont after suffering a heart attack. Her obituary said she was diagnosed with neuroendocrine cancer after falling ill three weeks ago.
Riggs, a neuropsychologist and mother-of-three, was married to Levi Sanders, who ran unsuccessfully for a New Hampshire congressional seat in 2018.
Her obituary says she met Levi Sanders while the two worked at an emergency food shelter in Vermont.
Riggs, who attended both Brown and Harvard, was the director of behavioral medicine at Dartmouth Medical School for several years, and she started the Palliative Care Department for Dartmouth Medical Center.
She also owned Riggs Geriatric Psychology in Windsor, Vermont.
In an obituary loved ones wrote: 'Her last words were to tell her children how much she loved them and she was so sorry that she got sick.
'Her last moment was spent with her No. 1 cheerleader, her mother, holding her hand and whispering in her ear how much she loved her.'
It went on: 'Rainè loved to spend time picking berries with her family and then bringing them home and spending the whole day baking. She loved to take her children to festivals and always allowed her children to pick the weekend adventures. There was nothing she would not do for them.'
Bernie Sanders said on Tuesday he had wrongly ignored warning signs about his health before suffering a heart attack last week, but that he did not think the scare would damage his campaign for president.
Sanders, one of 19 Democrats competing to take on Republican President Donald Trump in the November 2020 election, suffered chest pains on October 1 while in Nevada for a campaign stop and abruptly canceled campaign events.
Outside his home in Burlington, Vermont, where he was recovering on Tuesday, the candidate told reporters he was 'feeling good, getting some work done' after what his campaign later said was a myocardial infarction, a medical term for a heart attack.
'I don't think it helps or hurts,' Sanders, 78, said of the health scare, adding that he was on his way to see a new cardiologist in Burlington.
'I must confess that I was dumb,' he said, explaining that he had been campaigning hard in the early voting states of Iowa and New Hampshire before the incident.
'And yet I, in the last month or two, just was more fatigued than I usually have been and I should have listened to those symptoms,' Sanders said.