Gold, who together with fellow businessman David Sullivan took a controlling share of the club three years ago, fell ill following their FA Cup game at Upton Park against Manchester United on Saturday.
Daughter Jaqueline tweeted: "Have taken my father into hospital.
"I think he's learnt a very harsh lesson not to go to football with bronchitis. Now has pneumonia and being assessed."
She added that her father was on 'very strong antibiotics.'
In March 2011, 76-year-old Gold needed hospital treatment for cholangitis and septicemia.