The emails come from the hack of former Secretary of State Colin Powell, and one chain shows him discussing the Democratic presidential nominee's health with donor Jeffrey Leeds.

Also back in 2015, Leeds & Powell discussed Hillary's health pic.twitter.com/dm4G1WJvus — Lee Fang (@lhfang) September 14, 2016

Clinton abruptly left a Sept. 11 memorial ceremony on Sunday and was later seen stumbling as she tried to get into her van. Her campaign later said she had been diagnosed with pneumonia days before. She and Trump have been under increased pressure to release more medical details in the days since.