The Virginia congresswoman was initially told she had Parkinson's, but doctors revised their diagnosis to a faster-progressing disease.
The Democrat from Northern Virginia shared her diagnosis on World Parkinson's Day.
“He’s proven himself to be deceitful & inept as HUD Secretary,” Rep. Jennifer Wexton (D-Va.) said Thursday, echoing similar criticisms of his competency.
“I wanted to show my solidarity because we are talking about my friends and family," she said.
Hillary Clinton won the Virginia district by 10 points in 2016, and Comstock couldn't overcome her constituents' dislike of President Donald Trump.
There are women running for six out of the state's 11 House seats.