If Sigmund Freud had been any good at hypnotising people, the history of psychotherapy would be very different today. Freud gave up on hypnosis because, first, he wasn’t good at it and, second, he didn't think hypnosis was necessary to achieve results. He went on to develop his preferred method of psychoanalysis, and the rest is history.
Be that as it may, hypnotherapy has come a long way. Professionally trained hypnotherapists do much more than induce their clients into trance states. Being in hypnosis is pleasant, but it is not therapy. The real work is done by you, the client, with the hypnotherapist facilitating change at the subconscious level. And it’s at the subconscious level that change has to happen. For example, say you're trying to quit smoking using your will power only. Not only are you obsessed with smoking, but you are grieving the loss of a friend, the cigarette. After hypnotherapy to quit smoking, you easily forget about those cigarettes, because you’ve instructed the subconscious mind during hypnosis that smoking is an old habit that you're done with.
Working with the subconscious mind often involves resolution and the re-imagining of new and better outcomes. It involves you accessing your own, unique inner resources to assist you in achieving the outcomes you desire. The approach taken by the hypnotherapist is always in tune with your own circumstances, intentions, and desired outcomes.
Why see a hypnotherapist? Because it's fast and elegant. You don’t have to sign up for a lifetime of sessions, going over and over the same old stuff, hoping for some resolution along the way. Depending on the issue, you can expect one to six sessions of hypnotherapy. How do you know it’s worked? When you realise one day that you’ve forgotten all about that old issue.