tract infections and respiratory infections. Pneumonia can be accompanied by shortness of breath, fever, and anxiety. Another potentially deadly threat to respiration is deep venous thrombosis (DVT), in which blood forms a clot in immobile limbs; the clot can break off and form a pulmonary embolism, lodging in the lung and cutting off blood supply to it. DVT is an especially high risk in SCI, particularly within 10 days of injury, occurring in over 13% in the acute care setting. Preventative measures include anticoagulants, pressure hose, and moving the patient's limbs. The usual signs and symptoms of DVT and pulmonary embolism may be masked in SCI cases due to effects such as alterations in pain perception and nervous system functioning. Urinary tract infection (UTI) is another risk that may not display the usual symptoms (pain, urgency, and frequency); it may instead be associated with worsened spasticity. The risk of UTI, likely the most common complication in the long term, is heightened by use of indwelling urinary catheters. Catheterization may be necessary because SCI interferes with the bladder's ability to empty when it gets too full, which could trigger autonomic dysreflexia or damage the bladder permanently. The use of intermittent catheterization to empty the bladder at regular intervals throughout the day has decreased the mortality due to kidney failure from UTI in the first world, but it is still a serious problem in developing countries. An estimated 24–45% of people with SCI have disorders of depression, and the suicide rate is as much as six times that of the rest of the population. The risk of suicide is worst in the first five years after injury. In young people with SCI, suicide is the leading cause of death. Depression is associated with an increased risk of other complications such as UTI and pressure ulcers that occur more when self-care is neglected. Causes Spinal cord injuries are most often caused by physical trauma. Forces involved can be hyperflexion (forward movement of the head); hyperextension (backward movement); lateral stress (sideways movement); rotation (twisting of the head); compression (force along the axis of the spine downward from the head or upward from the pelvis); or distraction (pulling apart of the vertebrae). Traumatic SCI can result in contusion, compression, or stretch injury. It is a major risk of many types of vertebral fracture. Pre-existing asymptomatic congenital anomalies can cause major neurological deficits, such as hemiparesis,