Your brain is well protected from most damage. It sits inside a hard, bony skull. Layers of membranes and fluid provide even more padding. But even with all of this natural protection, the brain can still get injured. And damage to it can affect everything you do, from thinking to moving. A traumatic brain injury (TBI) is any blow to the head that's hard enough to affect the brain's function.
How Your Brain Can Get Hurt
A hard blow to the head can shake the brain inside the skull, resulting in bruising, broken blood vessels, or nerve damage to the brain. When you take a hard hit to the head but there's no outward bleeding or opening in the skull, it could result in a closed brain injury. An open brain injury is when an object penetrates the skull and goes into the brain.
Brain Injuries: Mild vs. Severe
A TBI can be mild or severe. A concussion is a mild TBI -- you should recover pretty quickly. A severe TBI can do enough damage to knock you unconscious for a longer period of time. It can even lead to a coma or death.
What is a Concussion?
A concussion is caused by a jolt that shakes your brain back and forth inside your skull. Any hard hit to the head or body -- whether it's from a football tackle or a car accident -- can lead to a concussion. Although a concussion is considered a mild brain injury, it can sometimes leave lasting damage. This is more likely if you don't rest long enough to let your brain fully heal afterward and you reinjure your brain.
How Do You Know It's a Concussion?
After a fall or hit to the head, you may be knocked out for a few seconds. But many people with concussions do not black out. A few telltale symptoms will show that you may have a concussion. Dizziness, nausea or vomiting, blurry vision, headache, and trouble thinking clearly are all signs that you need to see a doctor to get your head injury checked out.
Healing After a Concussion
Just like you need to rest your ankle after a sprain, you need to rest your brain after a concussion. Get plenty of sleep to give your brain time to heal. Ease back into activities like school and work slowly when you start feeling better. Stay off the playing field until your doctor gives you the OK. Getting a second concussion before the first one has healed can slow your recovery and increase the risk for permanent damage.
The skull is pretty tough. But if it's hit hard enough, it can crack. That's called a skull fracture. If the sharp edges of a fractured skull bone press into the brain, they can damage the delicate tissues and lead to bleeding in the brain. One sign of a skull fracture is clear fluid or blood draining from the nose or ears.
Bleeding in the Brain
Your brain can bleed if it's injured and blood vessels inside it are damaged. The trapped blood can pool, forming a hematoma. (Intracranial hematomas occur inside of the skull and usually you do not see a bump. You would see or feel a bump if it is a superficial bleed outside of the skull.) If the hematoma puts pressure on the brain, it can squeeze or cut off blood flow to the brain -- a medical emergency. Signs of a hematoma include headaches, vomiting, and trouble with balance.
Diagnosing Brain Injuries
Your doctor can tell whether you have a brain injury by doing a series of tests. You may be asked questions to check your memory, concentration, problem-solving ability, and other brain functions. If you have long-lasting or more severe symptoms, you may have a brain scan called a CT or MRI.
Brain Injuries and Memory
An injury can damage the parts of your brain you need to store and retrieve information. That's why you may have a harder time remembering your birthday, what you ate for breakfast, or the accident that caused your brain injury. Some memory loss after a brain injury is normal, but it should come back. People with severe brain injuries sometimes lose their memory for longer periods of time.
Brain Injuries and Movement
An injury can also damage parts of your brain that help you balance and walk. As a result, you may feel dizzy -- like the room is spinning. Parts of your brain that help you see clearly and gauge depth may also be affected. Physical therapy and other rehabilitation can improve your balance and movement after a head injury.
Brain Injuries and Mood
You may not feel like yourself after a TBI. Up to half of people experience symptoms of depression -- including persistent sadness and sleeplessness. Some have wild mood swings -- laughing one minute and then crying the next. Others feel overly angry or anxious. If you can't control your emotions, talk to your doctor about treatments.
Long-Term Effects of Brain Injuries
A serious brain injury can stick with you for life. Problems thinking, moving, and controlling your emotions may not go away, especially if you've taken many hits to the head (from sports, for example). There's some evidence that having a TBI increases your risk for Alzheimer's disease, Parkinson's, and other brain disorders as you get older.
Recovery from Severe Brain Injury
For mild injuries like concussions, the best therapy is to rest and give your brain a chance to heal. Physical, occupational, and speech therapy can help with the physical and mental side effects of severe brain injuries. Counseling sessions with a psychologist or psychiatrist can help you learn to live with your injury.
How Common Are Brain Injuries?
Every year, about 2.5 million people have an accident that leads to a traumatic brain injury. Most head injuries are mild, including concussions. But hundreds of thousands of serious brain injuries happen every year.
Children and Brain Injuries
Brain injuries rank among the leading causes of disability and death in children. Nearly half a million kids -- more boys than girls -- visit an emergency room for a brain injury each year. Kids with TBI can have more trouble learning, compared with their peers. They may also struggle with behavioral and emotional problems.
Is It Just a Bump on the Head?
Learning to walk is a wobbly time. An unsteady toddler can take a lot of tumbles. Luckily, kids are pretty resilient, and most bounce right back from a small bump on the head. But if your child won't stop crying, is throwing up, says his head or neck hurts, or has trouble waking up after a fall, call the doctor right away.
Safety on Bikes
Once they reach school age, kids are at risk from sports injuries and bicycle and car accidents. Teach kids to wear closely fitting helmets and other safety gear during sports and recreational activities. And make sure they follow bike safety rules about traffic and road hazards.
Head Injuries from Sports
Head injuries are common in professional and amateur sports like football, baseball, and hockey. Some professional leagues have even improved their sideline policies to treat athletes' head injuries more effectively. If you don't want to be carried off the field, wear a helmet that fits snugly every time you play. Supervise kids so they don't get too rough or play sports that aren't right for their age. And obey the rules to prevent falls and head-on collisions.
Safety in Cars
A car accident can thrust your head forward -- or worse, propel you from the vehicle headfirst. Before you put the key in the ignition, put on your seatbelt and buckle your child in an age-appropriate safety seat. Teach kids to wear seatbelts when riding in cars or school buses.
Preventing Head Injuries from Falls
You don't have to fall far, or hard, to hurt your head. To avoid taking a tumble, clean up the clutter, cords, and other hazards that may cause you to fall. Install lights above hallways and stairs so you don't stumble while going to the bathroom at night. Secure all rugs and mats firmly to the floor so they don't slide around.
(2) Bruce Ayres / Stone
(4) Nucleus Medical Art, Inc.
(5) Terry Vine / Blend Images
(6) Image Source
(7) Zephyr / Photo Researchers, Inc.
(8) Zephyr / Photo Researchers, Inc.
(9) Mike Powell / Digital Vision
(11) Denkou Images / Cultura
(12) John Lund/Marc Romanelli / Blend Images
(13) Glow Wellness / Glow
(14) Don / Design Pics
(16) Leah / Design Pics
(17) Laurence Monneret / Stone
(18) Jupiterimages / Comstock
(19) Jeff Greenberg
(20) Thomas Northcut / Riser
(21) Steve Pomberg / WebMD
American Academy of Family Physicians. "Head Injuries." "Head Injuries--Complications."
American Association of Neurological Surgeons. "Sports-Related Head Injury."
Brain Injury Association of America. "Diagnosing Brain Injury."
CDC. "Concussion and Mild TBI," "What to expect after a concussion," "What are the Potential Long-Term Outcomes of TBI?," "Clinical Diagnosis and Management."
Dana Foundation. "Brain Trauma, Concussion and Coma -- The Dana Guide."
McGill University. "The Brain from Top to Bottom."
Medscape. "Neuropsychiatric Sequelae of Traumatic Brain Injury." "Traumatic Brain Injury in Children."
Merck Manual Home Edition. "Skull Fracture."
National Dissemination Center for Children with Disabilities. "Traumatic Brain Injury."
National Highway Traffic Safety Administration. "Kids and Bicycle Safety."
National Institute of Neurological Disorders and Stroke. "Traumatic Brain Injury: Hope Through Research," "NINDS Traumatic Brain Injury Information Page."
Nemours Foundation. "Head Injuries," "Concussions."
News release, American Psychological Association.
News release, National Football League.
NIH. "Head Injury."
U.S. Department of Health and Human Services. "Treating Clients with Traumatic Brain Injury."
University of Washington Medical Center. "Memory and Brain Injury."
Virginia Commonwealth University. "Emotional Problems After Traumatic Brain Injury."
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for general informational purposes only and does not address individual circumstances. It is not a substitute for professional medical advice, diagnosis or treatment and should not be relied on to make decisions about your health. Never ignore professional medical advice in seeking treatment because of something you have read on the WebMD Site. If you think you may have a medical emergency, immediately call your doctor or dial 911.