Madeleine Nowak, 73, was found alive and well on Sunday morning after she became separated from a tour group on the island's Great Walk on Thursday.

After spending three nights sleeping rough in hot conditions, she walked out from the scrub onto Eastern Beach and approached campers who alerted police.

Ms Nowak, who has previous trail walking experience, was then reunited with her husband.

"It was extremely emotional," Acting Inspector Brooke Flood told reporters.

"Everybody involved in the search effort was just so relieved.

"It's been a really, really long three days."

Ms Nowak is in good health and expected to be released from Hervey Bay Hospital after undergoing precautionary checks.

LifeFlight's Brent Morgan said Ms Nowak left the trail after coming across a fallen tree on the track.

She decided to go around it before becoming disoriented and unable to rediscover the path.

"The last few days she's been heading east," Mr Morgan said.

A land, air and sea search and rescue commenced on Thursday evening and continued throughout Friday and Saturday.

Those searches were halted at night and restarted each morning at first light.

Ms Nowak knew air crews were looking for her but was not able to wave them down in difficult terrain.

"The bushland's very dense and very thick," Insp Flood said.

"The missing person actually said she heard choppers overhead but because of the canopy she just couldn't get their attention."

Ms Nowak is believed to have walked 6-7km from where she was last seen, making it harder for authorities to pin down her whereabouts.

Police have reminded adventurers to stay put if they become lost or disoriented to aid rescue efforts.

"If you stay as near as possible to where you have gone missing, the chances of you being located during a search dramatically increase," Insp Flood said.

Australian Associated Press