My leg is giving me much less pain but still aches when I sit down.

我的腿疼痛减轻了许多，但是当我坐下时还是会疼。

《柯林斯英汉双解大词典》

This, of course, can lead to less pain.

当然，这可以减少疼痛。

youdao

Women who receive the injections feel less pain.

接受了（肉毒杆菌素）注射的女性会感觉到疼痛的减少。

youdao

In addition,those using swear words said they experienced less pain than those who used control words.

VOA: special.2009.08.18

Which of these branches that are available to me, the branches of my life story, which is the one in which the future from here on out ?" holds more pleasure and holds less pain?"

我能得到哪些分支，我的人生故事的分支，从这里起步的哪一种未来,有更多快乐更少痛苦“

耶鲁公开课 - 死亡课程节选

"A needle that goes through the skin needs to be as sharp as possible because that's going to be associated with the easiest access, the more slick closure, and the less pain when somebody has, say their blood drawn or their skin closed."

VOA: special.2010.02.10

This solution is not painless, but I believe it will create less pain and shared pain.

FORBES: Can The Fiscal Cliff Be Avoided With A Surprisingly Simple Solution?

It suppresses a chemical in the body which affects inflammation and offers the patient the possibility of reduced stiffness and less pain.

BBC: NEWS | UK | England | Devon | Hospital gives arthritis drug

The study found that volunteers with two copies of the "val" gene were better able to break down dopamine and suffered less pain.

BBC: Gene controls pain threshold