Hypnosis can help patients working on issues such as smoking cessation, weight control, nail biting, phobia mastery, insomnia, anxiety, including PTSD, poor sexual function, obsessive thinking, and stress-related problems that might be rooted in such physical problems as hypertension, headache, or chronic pain problems. Hypnosis can be an effective aid in treating these problems. But not enough psychiatrists, psychologists, and psychotherapists use hypnosis or understand what it can and cannot do.