Interoception incorporates the afferent signalling, central processing and neural and mental representation of internal bodily signals. Historically, within the fields of physiology, psychology and neuroscience, there has been inconsistency in the way that individual differences in interoception are defined and measured. This talk will detail empirical results which demonstrate dimensions of interoception with and without conscious access, with a particular focus on the heart. In normative samples, these interoceptive dimensions are distinct and dissociable. The integration of afferent signals with brain can augment or attenuate perceptive, cognitive and emotion processing. Selective alterations in interoceptive processing are evident in clinical conditions such as schizophrenia and autism, while specific interoceptive disturbances are associated with transdiagnostic symptom expression such as anxiety and dissociation. Understanding the multifaceted nature of interoception and body-brain interactions can open up new avenues for targeted treatment.