Well, a lot could happen. Stab wounds are low velocity penetrating trauma that causes localized injury to the site that it touches. So injury pattern is dependent on the location, depth, blade type, and whether any internal movement or rotation was done during the incident. Injury to the lungs/thorax/pleural space could cause hemo/pneumothorax that could tension. Could cause cardiac tamponade, direct heart injury/laceration. Direct vascular/spinal injury. Associated muscle/soft tissue scarring/injury. Associated risk of infection. The kidneys are located retroperitoneal and are fairly high up on the back, so those could be impacted. Diaphragmatic tears and esophageal injury are possible. Generally, symptoms shown and associated sonography and imaging will assist in injury diagnosis and treatment response. Symptoms will generally include worsening shortness of breath and pain, numbness if spinal cord was affected. Supportive care generally involves o2 support, blood administration, pain medication, antibiotics and surgery, dependent on severity.