A person or thing that closely resembles another, as in Our grandson is a carbon copy of his dad. Originally this term meant a copy of a document made by using carbon paper. The linguistic transfer to other kinds of duplicate survived the demise of carbon paper (replaced by photocopiers, computer printers, and other more sophisticated devices). [ c. 1870 ]
The severity of symptoms depends on whether the injury is mild, moderate or severe. 1  Mild traumatic brain injury, also known as a concussion, either doesn't knock you out or knocks you out for 30 minutes or less. 2  Moderate traumatic brain injury causes unconsciousness lasting more than 30 minutes. Symptoms of moderate traumatic brain injury are similar to those of mild traumatic brain injury but more serious and longer-lasting. Severe traumatic brain injury knocks you out for more than 24 hours. Symptoms of severe traumatic brain injury are also similar to those of mild traumatic brain injury but more serious and longer-lasting.
Symptoms of post-traumatic stress disorder (PTSD) can be terrifying. They may disrupt your life and make it hard to continue with your daily activities. It may be hard just to get through the day. PTSD symptoms usually start soon after the traumatic event, but they may not happen until months or years later. They also may come and go over many years. If the symptoms last longer than 4 weeks, cause you great distress, or interfere with your work or home life, you may have PTSD. Even if you always have some symptoms, counseling can help you cope. Your symptoms don't have to interfere with your everyday activities, work, and relationships.