Yolanda Foster has been battling Lyme disease for nearly four years, and on social media, the reality star and mother of three continues to keep fans in the loop with her struggles.

Kyle Richards Claims She 'Knew Nothing About' Lyme Disease During Season Six

In one of her latest posts on Instagram, the Real Housewives of Beverly Hills shared some sad news with her followers, revealing a man named David had died after being diagnosed with Lyme disease.

"R.I.P DAVID GERAGHTY........ Your legacy will be one of the Warriors who's spirit will carry on helping to bring change," Foster wrote on Sunday. "#ChronicLymeDiseaseAwareness #SilentKiller #BORELLIA #WeMustFindACure #DavidGeraghty @lymestats @globallymealliance #LymeReality."

Did 'RHOBH' Star Lisa Rinna Defend Her Comments About Yolanda Foster On Twitter?

According to Foster's photo message, which accompanied her writings, Geraghty had been misdiagnosed with ALS in 2014, and died last week after his wife sent a blood sample to a lab in California.

A photo posted by YOLANDA (@yolandahfoster) on Dec 27, 2015 at 8:20pm PST

Throughout the sixth season of The Real Housewives of Beverly Hills, Foster's Lyme disease has been highly talked about, and highly questioned. During last week's episode, Lisa Rinna brought up the idea of Munchausen Syndrome, suggesting others have felt Foster may not really be struggling with the illness. However, after speaking of the disorder, Rinna said she felt bad for speaking of the potential idea without Foster present.

For more Yolanda Foster, tune into The Real Housewives of Beverly Hills on Tuesdays at 9 p.m. on Bravo.

Tags: yolanda foster The Real Housewives of Beverly Hills Bravo Reality TV