Tests have confirmed that TV entrepreneur Duncan Bannatyne did not suffer a heart attack in a health scare which saw him rushed to hospital, a company spokesman said.
The 63-year-old Dragons' Den star fell ill while at the headquarters of his gym business in Darlington and was taken by ambulance to the town's Memorial Hospital.
After an overnight stay, he is expected to be allowed home for a few days rest later.
A Bannatyne Group spokesman said: "Everyone at the company is relieved that tests have confirmed Duncan's health scare was not a heart attack and he will be discharged from hospital later.
"He is now to spend a few days recuperating from his chest pains away from the stresses of his busy life.
"He has asked us to thank the many hundreds of people who have contacted him to express their good wishes and support and to thank the dedicated staff at Darlington Memorial Hospital for the kindness and care."
He was well enough on Tuesday morning to tell his 540,000-plus followers on Twitter: "Just waiting for Doctors rounds but am sure I will get all clear to go home soon."
Bannatyne, who lives on the exclusive Wynyard estate in the countryside north-west of Middlesbrough, was born in Clydebank, Scotland and was raised in what he describes as "relatively modest circumstances".
His business interests now include health clubs, hotels, property, media and transport and he is best known as a tough-talking business angel on the BBC show Dragons' Den. The former Royal Navy stoker began his empire with an ice cream van, rapidly expanding that business in tough competition before setting up a chain of care homes.
On his website he says he sold that for £26 million in 1996 and his children's nursery chain for £22 million. He has written five self-help books on becoming a success in business and managing money, was awarded an OBE for his charity works and is a vehement anti-smoker.