Cindy Crawford opens up about her late brother's initial signs of leukemia

Cindy Crawford's family learned about her younger brother's cancer diagnosis when his body reacted unusually to physical punishment.

The supermodel, 59, made an appearance on the Kelly Corrigan Wonders podcast on Friday.

At one point, the conversation shifted to the death of her three-year-old brother Jeffrey from leukemia.

Crawford recalled how she and her three siblings used to be spanked by their parents when they were young kids.

"I know this sounds very, like, child abuse, but, you know, we definitely were spanked as kids," she told the host.

"My mother, she would say, 'Go to your room, you're getting a spanking.' And that waiting period to your point was just like the worst."

The family wasn't aware of two-year-old Jeffrey's condition until they saw his body react unusually to the physical punishment.

"I have a brother who died and he had leukemia, and before we knew he had leukemia, one of the symptoms of leukemia is you bruise super easily," the model continued. "My dad had, like, swatted him, but it left like a handprint on him."

Crawford recalled her mother confronting their dad about it, telling him, "You can't be hitting the kids that hard, you know, that's not a spanking."

"And my dad was like, 'No, I swear I barely touched them.' And then later that week, we found out that he had leukemia, so I think that that was it. My dad... he never could spank again."

"Jeff was like 2, turning 3 when he got diagnosed, and then he was sick for two years."

According to the City of Hope's Cancer Center, leukemia—which is a cancer of the body's blood-forming tissues, including the bone marrow and the lymphatic system—can cause bruising very easily, because their bodies don't produce enough platelets to clot bleeding blood vessels.