"The first verse of the song describes a typical situation, namely: the drug addict in withdrawal crisis who goes to all his friends asking for money for a fix.

In the second verse, there is a specific reference to his own band, and the loss of a companion despite attempts to help him.

The third verse expresses the motivation behind this song, which is to share the experienced reality with his audience, to make them understand what really happens, reminding them that it is not a generic plea because there is a flesh-and-blood man behind it, a friend of his.

In the last line, he also includes a raw and realistic reference to the lives of heroin addicts, and it's the act of trying to recover even that small amount of blood left in the syringe, because it still contains a tiny bit of drug.

The fourth is intended to make those who listen to the song understand that many have experienced some form of dependency, whether physical or psychological, and thus can comprehend that heavy drug use is a terrible catastrophe that inevitably leads to night, but not to a new day..."

Neil Young - Needle And The Damage Done [Unplugged]