England spinner Jack Leach said he surpassed his own expectations after getting his 100th Test wicket on Saturday, calling it a "special" achievement.

On day two of the second Test against Pakistan, Leach dismissed Saud Shakeel to reach the milestone in his 31st Test.

The left-armer ended the innings with 4-98, having helped put England in command of the match.

"I just felt like... 100 wickets feels like quite a lot," said Leach after stumps on the second day. "And it's more than I felt I'll ever achieve."

"I need to remember that. As sportsmen and as people, it's easy to just push on to the next thing and the next thing and the next thing, and nothing's ever enough."

"If you told me that when I was a kid that I’d take 100 wickets, I would have laughed at you," he added.

"So yes, it is special."

Leach has had health struggles during his career, including Crohn's disease, a bowel condition.

"I'm aware everyone has their challenges, I'm aware mine have been quite out there. That's good because I want to be open and honest with people," he said.

"There's been some definite lows along the way, but it does sort of make it all worth it."

England lead the three-Test series 1-0, having won the first match in Rawalpindi by 74 runs.