Spinal cord injury and especially cervical spinal cord injury implies serious disturbances in autonomic nervous system function. The clinical effects of these disturbances are striking. In the acute phase, the autonomic imbalance and its effect on cardiovascular, respiratory system and temperature regulation may be life threatening. Serious complications such as over-hydration with the risk of pulmonary edema or hyponatremia are seen. The cord-injured person suffers from autonomic nervous system dysfunction also affecting bladder and bowel control, renal and sexual function. Paralytic ileus may cause vomiting and aspiration, which in turn interferes with respiratory function in those with cervical spinal cord injury. The cord-injured person is at risk to develop pressure sores from the moment of the accident. Two to three months post-injury the cord-injured person with a lesion level above the fifth thoracic segment may develop autonomic dysreflexia, characterised by sympathetically mediated vasoconstriction in muscular, skin, renal and presumably gastrointestinal vascular beds induced by an afferent peripheral stimulation below lesion level. The reaction might cause cerebrovascular complications and has effects on metabolism. Some of the autonomic disturbances are transient and a new balance is reached months post-injury, while others persist for life.