Many languages do not use "How are you?" as a standard greeting. Mandarin speakers usually say "Ni hao," which word-for-word means "You good." It's not a question; the question form would be "Ni hao ma?", and is not used as a greeting at all.

My father, who spent a couple years in Thailand decades ago, says that the Thai phrase meaning "How are you?" was invented (or at least popularized) in response to Westerners' demand for such a phrase. Does anyone have any information supporting or undermining this?