context: Injuries can happen to your brain in many ways. They could be brought on by medical problems like a stroke or tumor. These are called acquired brain injuries ( ABIs). But most often, brain injuries are due to a violent blow or jolt to the head. These are called traumatic brain injuries ( TBIs). TBIs can damage nerve cells and cause bleeding or swelling in your brain. Most TBIs are treatable, but they can impact your daily life and cause you physical, mental, or emotional stress. These injuries can happen as a result of: A blow to the head. These are called closed head injuries. Common causes are impact sports and car accidents. Not every hit to the head will result in a TBI, but if you have any concerns, see your doctor. Penetration. An object such as a bullet breaks through the skull and hits the brain. This is known as an open head injury. Severe shaking of the head. This causes nerve tissue to tear. This is common in infants, and in them it's known as shaken baby syndrome. Whiplash. The quick back-and-forth can cause a brain injury. A TBI can cause you to lose consciousness, have amnesia for a while, or be confused for weeks. A TBI from a crushing or a penetrating blow can be life-threatening and life-altering. You'll most likely need surgery and rehabilitation. Concussions are the most common type of TBI. They aren't usually life-threatening, but there are dangers. These injuries may not show up in initial tests and could take as long as a few years to completely heal. Immediate symptoms can be loss of consciousness or feeling dazed and confused. But it may take a while before you have any symptoms. If you take a hit to the head, be on the lookout for these symptoms: Balance problems Blurred vision Dizziness Delayed response to questions Headaches Memory loss Nausea Ringing in the ears Seizure Slurred speech Vomiting This form of TBI is when you have bruises on the brain that cause bleeding. If the area is large enough, you may need surgery. See a doctor if you think you have had any kind of brain injury. And follow your doctor's orders. TBIs can cause any number of problems. Physically, you need rest. But mentally and emotionally, you may feel exhausted, too. You may not be able to think or communicate well, and it can dull your sensory skills. Be on the lookout for changes in these areas, among others: Anxiety Depression Memory Muscle function Poor judgment Sight Sound Smell Taste Touch Understanding TBIs can increase the risk of brain diseases, such as Alzheimer's and Parkinson's. If you have had a TBI, take steps to avoid another injury to your brain. Even with mild TBIs, repeated injuries can do long-lasting damage to your nervous system and weaken your mental awareness. If TBIs continue to happen over a short period of time, they could lead to death. Make sure your first TBI has fully healed. Although concussions are generally listed as mild, getting a second concussion before the first one has healed can be deadly. This is known as second impact syndrome. Second impact syndrome causes rapid and severe brain swelling. The symptoms are almost immediate and include the following: Dilated pupils Loss of eye movement Respiratory failure Unconsciousness Symptoms will progress rapidly. At the very least, it will result in severe TBI and have long-lasting effects that will change your everyday life. Acquired brain injuries ( ABIs) aren't caused by trauma. They're caused by other forces, such as a stroke, tumor, fluid, or infection that happens after birth. Often, they cause the brain not to get enough oxygen. ABIs can be severe, sometimes leaving you unable to control daily aspects of your life. Like TBIs, they can cause problems with movement, thinking, emotions, and behavior. The effects of brain injury are different for everyone. Your treatment and recovery will depend on the cause of your injury, the location, and how severe it is.