This must be something that is different between different cultures. Here in the US, we do not think of ginger in this way. Also, where I grew up in Micronesia, ginger was not used for healing.
However, many people believe that ginger is useful for many problems. They say that it cures nausea from things like motion sickness or morning sickness. They also say that it can reduce the pain caused by arthritis.
The answer is simple: nobody knows. And it seems that human intelligence will never fully understand the mode of action of ginger. Ginger has, as far as we know today, nearly 500 compounds identified, many with known biological activities, acting in a complementary manner to produce biological benefits. Each compound has a particular effect or influences a particular enzyme or protein, or it is supporting the action of other compounds.