Given help in learning to manage their anxiety, they are much better able to handle their condition. Biofeedback, then, is a tool, an educational aid, for learning valuable skills. In practice many of the psychologists who use Relaxometers do so in a psychotherapeutic way, but that is because of the clients they see, and is not necessary. The Relaxometer can give very valuable insights to people with no psychological problems at all - just a stress problem. Biofeedback instruments are all intrinsically very safe, because they depend on the user having the motivation to continue to use the feedback sound to control themselves.
Any discomfort removes the incentive to continue.
The Relaxometer and similar instruments provide biofeedback of just one measure, Galvanic Skin Response, because it is simple, quick and useful. GSR is a key indicator of the Fight or Flight reaction in the autonomic system. Autonomic arousal is easy to recognize when it is extreme - we break out in a sweat. But such a strong sign is rare, and it is the job of GSR instruments to make clear to the user the much smaller changes that do occur all the time, but that we do not usually notice. They can be caused by as simple a thing as a noisy vehicle passing, or the realization we have forgotten to do something.