Young missed the first two games of this series against the Braves with symptoms related to high blood sugar, which included blurred vision and lightheadedness.
Young will return to Washington on Sunday to be reevaluated by a team doctor. He will likely receive new medication to stabilize his diabetes, which he has battled since November 2006.
"This is all new to me, and we're going to take all the necessary steps for me to start feeling better again," Young said.
Young did not know what triggered these latest symptoms, saying, "That's the thing with diabetes -- it's a monster."
The 34-year-old was a late scratch from Friday's game after experiencing blurred vision when his blood-sugar level spiked. After he was injected with insulin, Young attempted to take batting practice but told manager Manny Acta he was not well enough to play.
Young was examined by Braves associate physician Dr. Brooks Lide after Friday's game, and Lide told him that if he kept his blood sugar in check he should be able to play this weekend.
Young's condition worsened when he arrived at Turner Field on Saturday, telling a team spokesperson that he was lightheaded and had difficulty focusing.
Because he missed the final two games before the All-Star break with lower back stiffness, Young's DL stint is retroactive to July 12. He is batting .280 with four homers and 10 RBIs in 50 games this season.
Zimmerman, rehabbing from a small labrum tear in his left, non-throwing shoulder, has gone 2-for-11 with a double in three games with Columbus. He was also 3-for-10 with two doubles for Class A Potomac.
"It will be nice," Acta said of having Zimmerman back. "We'll be able to have a little more depth in our lineup. We'll have a threat in the lineup."
Zimmerman was placed on the DL on June 3, retroactive to May 26, after injuring his left shoulder sliding headfirst into second base on May 18. He is batting .257 with eight homers and 27 RBIs in 50 games this season for the Nationals.