That goes for orgasms and libido, just as it goes for happiness and sadness, love and pain, and all stages of awareness. It’s all very chemical, with hormones and neurotransmitters the main players. Sensual input and emotional output are an overlay, through which neurobiochemistry communicates with the outside world.
It’s in our genetic constellation that certain biochemical states appear pleasant and others don’t. There is a wide range of variation, as some people even consider certain manifestations of pain, including suffocation, as erotic, and others have a very limited capacity for love.
There are, in principle, two methods by which we can interfere with our brain chemistry.
Either pharmacologically, via the supply of chemicals, or non-pharmacologically.
Good non-pharmacological methods are many forms of sexual activity, other pleasurable endeavors, from food to music, thrills like skiing or rock climbing, physical exhaustion by running or biking, or hypnosis and meditation. The purpose of all the above is the endogenous release of neurochemicals that make us feel good.
On the other side of the strata are chemicals that directly induce positive feelings, of which opiates are the best example. On the right opiates, one feels good whatever one’s actual condition. Philosophically, opiates are one of the greatest achievements of mankind, as they allow us to engineer a gentle death.