They studied 200 patients with an average age of 60 and discovered that those on a low dose had double the reduction in knee pain of patients on higher doses.

他们研究了平均年龄为60岁的200名患者，发现在减少膝盖疼痛的效果上，那些少量服用鱼油的病患是大量服用的病患的两倍。

youdao

During my visit to urgent care, starting about 1pm and continuing until 7pm, my respiration rate was double to triple its normal rate. My lungs are bags of pain that trap CO2.

我在急诊处的这段时间，从下午1点一直到7点，呼吸频率达到了正常频率的两倍到三倍，肺里充满了二氧化碳、非常疼痛，发着高烧。

youdao

With friends, sharing the pain is half the pain, to share the joy of double happiness.

与朋友在一起，分担的痛苦是减半的痛苦，分享的快乐是加倍的快乐。

youdao

If there's a recession, the pain will double.

FORBES: Bigger, Faster And, Yeah, They Burn More Gas

Here he is describing the pain of being a double amputee.

NPR: 'Pulled from the Rubble '

They end up bent double, on zimmer frames, with pain, particularly pelvic fractures which are almost impossible to control in terms of pain.

BBC: Breakfast with Frost