An 84-year-old Texas man became the nation’s oldest living kidney donor recently, when he knocked on his ailing 72-year-old neighbor’s door and offered to help her out.

Linda Nall, who has lupus and was suffering from kidney failure, said she assumed Frank Dewhurst was knocking on her door to tell her that her sign looking for a "type O" donor was against Homeowner’s Association rules, according to a press release from Houston Methodist Hospital.

“When he told me he wanted to give me his kidney, I was shocked,” Nall said, according to the news release. “It’s an incredible thing he has done for me and I am so grateful.”

'SLUG'-SIZED GROWTHS REMOVED FROM WOMAN'S NOSE AFTER COMPLAINTS OF BREATHING ISSUES

Dewhurst said he had known his neighbor was struggling with kidney issues, but after seeing his sign he talked it over with his wife and decided to help.

“After undergoing a number of tests I was cleared to donate and very happy to do so,” he said.

Dr. Hassan Ibrahim, chief of kidney diseases at Houston Methodist Hospital, said that while it’s commonly thought that older patients would make poor donors, the hospital has worked with donors aged 80, 79 and others in their 70s and late 60s.

WHO CLASSIFIES 'BURNOUT' AS AN OFFICIAL MEDICAL DIAGNOSIS

“They receive a full workup to make sure they are physically strong to donate,” Ibrahim said in the press release. “If everything checks out, there is no reason to keep them from saving someone’s life. In 2018, 5 percent of kidney donors nationally were older than 65. If more older adults donated, fewer people would remain on the list.”

Ibrahim said Dewhurst’s kidney going to Nall was a great match due to their age.

Dewhurst has returned to his regular exercise activities, while Nall said she plans to “make the most of Frank’s generous gift and live life to the fullest.”

“I cannot wait,” she said, according to the press release.

CLICK HERE TO GET THE FOX NEWS APP

Over 60 percent of kidneys from living donors last more than 10 years, Ibrahim said, compared to 46 percent received from deceased donors.