Senate Minority Leader Mitch McConnell is “medically clear” to continue working, the attending physician for the U.S. Congress said one day after the Kentucky Republican froze up during a press conference for the second time this summer.

“Occasional lightheadedness is not uncommon in concussion recovery and can also be expected as a result of dehydration,” said Dr. Brian Monahan in a letter shared Thursday from McConnell’s office.

The doctor was referencing a concussion that McConnell, 81, had suffered in March after a fall at a political fundraiser.

Monahan said he has “consulted with Leader McConnell and conferred with his neurology team,” and gave him the all-clear after “evaluating yesterday’s incident.”

That incident came at the start of a Wednesday afternoon press conference in Covington, Kentucky, when McConnell abruptly stopped speaking and stared straight ahead for about 30 seconds.

He appeared to fail to respond when an aide approached him to ask if he had heard a reporter’s question. McConnell had been asked for his thoughts about running for reelection.

The episode echoed a similar health scare in July, when McConnell suddenly froze and was briefly unable to speak at a news conference in Washington, D.C.

But Monahan said in Thursday’s letter that he has “informed Leader McConnell that he is medically clear to continue with his schedule as planned.”

An aide to McConnell had previously described the lapse in Covington as the result of the senator feeling “momentarily lightheaded.”

McConnell participated in a discussion with Rep. Jim Banks, R-Ind., later Wednesday evening, his office confirmed to CNBC.

McConnell’s health is a growing cause for concern among some of his Senate colleagues, according to Politico, which reported that some GOP members are weighing whether to force a special conference meeting about the Republican leader’s recent incidents.