Severe health anxiety is a highly distressing, often debilitating, psychological problem. Since the release of the Diagnostic and Statistical Manual of Mental Disorders 5 (DSM-5) its clinical manifestations are increasingly often referred to as Somatic Symptom Disorder (SSD) or Illness Anxiety Disorder (IAD). Despite often being overlooked in routine care, several treatments for severe health anxiety have shown great promise, the most well-established being Cognitive Behavioral Therapy (CBT). Traditionally, CBT - like most other psychotherapies - has typically been delivered face-to-face. That is, the patient physically meeting with the therapist once a week for the whole of the treatment. Internet-delivered CBT does not rest on this requirement, but has nevertheless been shown to be efficacious for severe health anxiety (see for example NCT01673035).