Biofeedback is a method that uses the mind to control a body function that the body normally regulates automatically, such as muscle tension, heart rate, pain perception or stability...
The answer is not that clear. Several studies investigated how to alleviate back pain or headache pain using several methods among which the biofeedback techniques. In fact, I found no direct evidences that biofeedback is efficient to reduce pain. Thus, I am not really convinced. I would be glad to see a convincing review or study about the question...
Chronic pain as lower back pain, fibromyalgia etc. are known to deteriorate in severity, when peoples are stressed, depressed or under anxiety or negative feeling. So, it seems neurofeedback may help reduce pain intensity. Please refer to
Article The Effects of a Novel Psychological Attribution and Emotion...
Knowledge about the stress response and its effects on an individual’s physiology greatly increased. As a result, a large number of studies were conducted investigating the efficacy of hypnosis and biofeedback in the treatment of several pain conditions, including chronic pelvic pain, fibromyalgia, headaches, irritable bowel syndrome/gastrointestinal conditions, lower back pain, multiple sclerosis,18 and temporomandibular pain.
It is percieved that mind & body are connected: lots of genes are said to be influenced by mental state.
Biofeedbacks like positive feeling, attitude & gratitude etc. are known for pain reliefs. Gratitude is known to trigger release of anti-depressant and moody chemicals (serotonin, dopamine, norepinephrine and oxytocin) and inhibit the stress hormone 'cortisol.'