The lawsuit was filed Monday and served to the Atlanta Falcons Football Club on Tuesday, said Eric Farber, Jackson's San Francisco-based attorney.
While Jackson was a free agent last season, reports surfaced in April that he had heart issues and had failed a physical exam. The Falcons later signed Jackson, who is listed at 350 pounds and is one of the league's largest players, in August.
Jackson's lawyers claim the Falcons released the medical information and hurt his value in the free agency market.
"Essentially the Atlanta Falcons released private and personal health information to the press without authority when Grady Jackson was a free agent and not under contract," Farber said.
A spokesman for the Falcons said the team had been served with the lawsuit, but added there were other motives behind the suit.
"We are disappointed that Grady Jackson's agent has taken this action," Falcons vice president of football communications Reggie Roberts said, reading from a prepared statement. "We believe that this is a continuing attempt by the agent to gain a new contract for his client."
Jackson's agent, Angelo Wright of Hayward, Calif., denied he is behind the lawsuit.
"This is Grady Jackson's lawsuit, and it's time that they recognize that," Wright said.
It is rare for a player under contract to file a lawsuit against his current team. Usually, players have contract or injury grievances that are dealt with under the league's collective bargaining agreement with the NFL Players Association.