Diane Huggins, 59, was released by Ascension Resurrection Hospital on the Northwest Side Sunday morning, and had not been heard from since then.
She was treated there after becoming disoriented and confused, after missing a connecting flight at O'Hare airport.
Huggins walks with a cane, and uses hearing aids.
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She's described as 5-feet, 9-inches tall, weighing about 200 pounds and having brown eyes and brown hair, CPD said.
She was traveling from Maryland to Ohio, when the flight was missed at O'Hare.
CPD said Tuesday night that Huggins was found at the Chicago O'Hare Hilton at 9:30 p.m.
Family members have been notified.