A Spurs statement read: "Our Under-23’s coach received immediate treatment on site from our medical staff before being transferred to hospital by ambulance.
"Everyone at the club sends their best wishes to Ugo and his family.
"We shall continue to provide updates when we have further information."
We can confirm that Ugo Ehiogu is currently in hospital after collapsing at our Training Centre earlier today. pic.twitter.com/uLZkb3hYHS
— Tottenham Hotspur (@SpursOfficial) April 20, 2017
Ehiogu, who played for Aston Villa and Middlesbrough and was capped by England four times, has been on the coaching staff at Spurs since 2014.
Aston Villa paid tribute to the 44-year-old on Twitter with the message: "Get well soon, @UgoEhiogu! Everyone at #AVFC wishing you a speedy recovery."
— Aston Villa FC (@AVFCOfficial) April 20, 2017
Spurs' north London rivals Arsenal posted a message soon afterwards, saying: "All of us at Arsenal hope Ugo makes a full recovery - our thoughts are with him and his family".
@SpursOfficial All of us at Arsenal hope Ugo makes a full recovery - our thoughts are with him and his family
— Arsenal FC (@Arsenal) April 20, 2017
Ehiogu began his career as a trainee at West Brom before he was taken to Aston Villa by Ron Atkinson in 1991.
He went on to feature in more than 300 matches for Villa over a nine-year spell - and played in their FA Cup final defeat against Chelsea in 2000.
Ehiogu joined Middlesbrough for a then club-record £8million fee later that year, and in 2001 he scored his only goal for England in Sven Goran-Eriksson's first game in charge, a 3-0 friendly victory against Spain.
Knee injuries plagued the final years of Ehiogu's career at the Riverside Stadium.
He joined Leeds on loan in 2006, and also had short spells with Rangers and Sheffield United before he retired from football in 2009. Ehiogu subsequently moved into coaching and has been at Tottenham for the past three seasons.
Additional reporting by the Press Association.