This chapter provides a review of the main clinical alterations of body representation in neurological and psychiatric diseases. First, we describe instances of altered body representations in neurological conditions, either constrained to a specific body part (e.g., personal neglect, somatoparaphenia, phantom limbs) or impacting the whole body (autoscopic phenomena, feeling of a presence). In the second part of this chapter, we present body representation disorders associated with chronic pain and psychiatric conditions including anorexia nervosa, schizophrenia, and gender dysphoria. Beyond their clinical relevance, these conditions provide valuable insights into understanding the way our body is normally represented, and the way it is consciously experienced.