Ache in Chinese / Japanese...

疼 can mean hurt, ache, pain or sore in Chinese and old Korean Hanja.

It's also used to speak of the pain of love, and thus its definition also includes “love fondly.” This also means ache, hurt, tingle, or pain in Japanese but is not often seen as a lone Kanji like this in Japanese.

痛 means pain in Chinese and old Korean Hanja. It also means pain/hurt/bruise in Japanese but is seldom seen as a single Kanji (usually, at least a Hiragana is added to make the word “itai” which is what a Japanese person will scream when they are in pain).

Depending on the context, this word can mean hurt, ache, sorrow, or refer to damage to a human body. As a single character, the possible meanings are very open - so you can decide what it means to you, as long as the general meaning is still “painful.”

See Also:  Hurt

痛みなくして得るものなし is a Japanese phrase that means “no pain, no gain.”

This suggests that with pain, a gain must follow.

The pain Kanji here can also be translated as sorrow or suffering. The gain can also mean profit, advantage, or benefit. In the Japanese Buddhist context, that gain Kanji can mean rebirth in paradise, entering nirvana.

The character breakdown:
痛みなく (itami naku) pain; ache; sore; grief; distress. The naku part adds the meaning of “a lot of” or “extended”
して (shite) and then. (indicates a causative expression; acts as a connective particle)
得る (eru) to get; to acquire; to obtain; to procure; to earn; to win; to gain; to secure; to attain.
もの (mono) conjunctive particle indicating a cause or reason.
なし (nashi) none of; -less; without; no.

Note: Because this selection contains some special Japanese Hiragana characters, it should be written by a Japanese calligrapher.