In the UK, we say hello and then we say how are you? The response is fine unless it is a close friend who asks you in a particular way and you know they really want to know. A Spanish friend has instructed her mum that when she comes here she is to say fine and not to list all her ailments. A Polish person told me that she tried for a week at work to give real answers to the question to see if they really wanted to know. They didn’t.