The decomposed body of Margareta Scheibe, 72, was found by police and firefighters in the town of Worth, authorities said.
She and her 42-year-old son lived in a home filled with rubbish, stacks of newspapers and broken bicycles and toys, the Chicago Tribune reported Wednesday. Investigators in hazmat suits had to deal with a severe foul odor in the house when they first searched it Saturday and did not find her body until Tuesday.
Many areas of the house were blocked by huge stacks of garbage, police said.
Authorities said they were contacted by a friend of Scheibe's who had not seen her in a month. A neighbor said Scheibe never threw out old newspapers, and collected them at restaurants and in parking lots.
"She never even put the trash collection bin out on garbage pick-up dates," he added.
Police said no charges have been filed.