Head injuries can be as severe as a concussion, fractured skull, internal bleeding, and brain damage. In fact, head injuries are a major cause of disability and death in adults.1 However, they can also be as mild as a bump, bruise (contusion), or cut on the head. And not every hit to the head will even result in an injury.
That’s why it’s important to know the types of head injuries that can happen with a blow to the head and when to seek medical attention.
What Is a Traumatic Brain Injury?
A traumatic brain injury (TBI) is a head injury caused by a bump, blow, or jolt to the head or body or a penetrating head injury. A TBI results in disruption of normal brain function.2
TBIs can occur from direct hits to the head, vehicle accidents, or inflicted injuries (like an assault or suicide attempt), Angela K. Lumba-Brown, MD, clinical assistant professor of emergency medicine and neurosurgery at the Stanford School of Medicine, told Health.
However, the majority of these TBIs occur from falls, Dr. Lumba-Brown said. Falls are the second leading cause of TBI-related deaths.2
After a “significant blow to the head” in January 2021, comedian and actor Bob Saget was found dead in his hotel room in Orlando, Fla. According to a statement from his family to The Hollywood Reporter, the 65-year-old “accidentally hit the back of his head on something, thought nothing of it, and went to sleep.”3 It was later revealed in an autopsy report that Saget had multiple skull fractures and brain bleeding, The New York Times reports.4
Life-threatening brain injuries like Saget’s aren’t uncommon: According to the Centers for Disease Control and Prevention (CDC), about 61,000 people died from TBIs in 2019.5
While TBIs can result in severe medical complications, including brain bleeding, swelling, and death, knowing when to seek emergency medical care for yourself or another person can be life-saving. Here’s what you need to know about traumatic brain injuries, and what to do if you hit your head (especially if you’re alone).
Head Injuries Explained
Some of the different types of head injuries include:6
- Concussion: This is a jarring injury to the brain. You may remain conscious. You may feel dazed or have visual changes, headaches, neck pain, or other changes in cognitive function.
- Brain contusion: This is a bruise of the brain. Minor bleeding in your brain causes swelling.
- Skull fracture: This is a crack in your skull. Sometimes, the broken skull bones can cut into your brain which causes bleeding and can lead to another injury. Broken skull bones can also lacerate (cut) an artery in your skull and cause a collection of blood that presses on your brain, known as an epidural hematoma.
- Hematoma: This is a collection of blood that can occur inside the skull next to the brain or outside the skull under the scalp. It can appear right away or may take several days.
TBIs occur on a spectrum—the most common being a mild TBI or concussion. Hitting your head on a cabinet door, falling, or getting injured playing a sport might cause one of these mild TBIs, Dr. Lumba-Brown said.
And while you might experience pain and neurological symptoms from a concussion, a brain scan won’t show findings like bleeding, bruising, or swelling, Dr. Lumba-Brown added. The CDC says people who have a mild TBI or concussion usually feel better within a few weeks.1
Moderate or severe TBIs, however, will show up on brain scans—usually in a variety of ways. Hematomas—specifically epidural hematomas or subdural hematomas—are one way a TBI can manifest, Anthony P. Kontos, PhD, director of the University of Pittsburgh Medical Center Sports Medicine Concussion Program, told Health.
An epidural hematoma involves bleeding from a ruptured blood vessel in the space between the skull and the covering around the brain, called the dura mater. A subdural hematoma involves bleeding from a ruptured blood vessel between the dura mater and the area just outside the brain (the arachnoid).
Moderate to severe TBIs can also include contusions, bruising of the brain tissue; or hemorrhages—both intracerebral hemorrhages and subarachnoid hemorrhages—which is when active bleeding is present.7
These moderate to severe TBIs can be especially dangerous—any type of bleeding or swelling in the skull can increase pressure in the brain (known as increased intracranial pressure), which is a life-threatening situation, George T. Chiampas, DO, assistant professor of emergency medicine and orthopedic surgery at Northwestern University Feinberg School of Medicine, told Health.
The extra pressure in the brain can press on brain structures and restrict blood flow, which can lead to severe brain damage or death.8
TBIs can also progress from one degree to another, which is why it’s so important to seek medical care if you’re concerned. “[Epidural and subdural hematomas] can occur several days or even weeks following an injury to the head, so it is important to stay vigilant and monitor your symptoms,” Kontos said. “Do not hesitate to go to the ER if something feels off.”
Who’s Most At-Risk for Complications From Head Injuries?
TBIs can impact anyone, but some people are at a higher risk than others for severe problems. For example, people with bleeding disorders are at a higher risk for complications, Dr. Lumba-Brown said. People older than 65 years, who have thinner blood vessels and smaller brains, are also at a higher risk for severe injury.
Those with a condition called osteopenia, which causes people to lose bone mass and increases the risk of skull fractures, are considered high-risk, as well.
Taking blood thinners (including aspirin) is also a major risk factor. “Because blood thinners prevent blood clots from forming, even small cuts or bruises will bleed a lot more,” Kontos said. “Because of that, blood thinners may increase the risk of any bleeding in the brain.”
Lastly, people who might have difficulty explaining their symptoms—young children, people with dementia or memory problems, or patients who have a substance use disorder—are also at a higher risk, Dr. Chiampas said.
How To Know You Have a Head Injury
When you bump your arm or sprain your ankle, you can usually see physical signs of injury, which might prompt you to seek medical attention. Brain injuries, on the other hand, aren’t visible.
“It’s very different from other injuries where you can see bruising on your skin or swelling in your ankle,” Dr. Chiampas said. “That’s why it’s so important to be cognizant of developing symptoms and when to address them.”
Symptoms of mild TBI and concussion include:9
- Sensitivity to light or noise
- Dizziness or balance problems
- Feeling tired, no energy
- Headaches
- Nausea or vomiting (early on)
- Vision problems
- Attention or concentration problems
- Feeling slowed down
- Foggy or groggy
- Problems with short- or long-term memory
- Trouble thinking clearly
- Anxiety or nervousness
- Irritability or easily angered
- Feeling more emotional
- Sadness
- Sleeping less than usual
- Sleeping more than usual
- Trouble falling asleep
When Should You Seek Medical Care After a Head Injury?
It’s always a good idea to be evaluated by a medical professional after a head injury, even if it’s mild. According to Kontos, concussions can exacerbate existing issues like migraines, motion sickness, and anxiety and mood disorders.
Because head injuries can worsen over time, a healthcare provider’s input can also help you monitor your symptoms and impairments to make sure they aren’t getting worse.
Research suggests seeking medical help within one week of a mild head injury—one 2020 study found that people who sustained a head injury and sought medical attention within a week recovered faster than those who waited longer to seek help.10
Seeking a healthcare provider’s input is also essential for reducing your risk of other health complications from a TBI. Research from 2022 found that endocrine and cardiovascular conditions after TBI were significantly higher in patients with mild or moderate to severe TBI compared with patients without TBI.11
Moderate and severe TBIs, however, require emergency care right away, Kontos said. If you have any of these “red flag” symptoms after a head injury, call 911 or have someone take you to the emergency department right away:
- Loss of consciousness for any amount of time
- A severe headache
- One pupil that’s larger than another
- Dizziness
- Any type of weakness or decreased coordination
- Speech problems
- Confusion or difficulty thinking
- Seizure (shaking or twitching) for any duration
- Drowsiness or inability to wake up
- Repeated nausea or vomiting
Aside from noticeable symptoms, Dr. Lumba-Brown said anyone who is considered high risk for complications of a head injury should be seen by a medical professional right away. If you sustain a head injury while you’re alone, you should take extra precautions as well, like telling someone else about your head injury or calling your provider (or scheduling a telemedicine session) to find out if and when you should seek treatment.
And if you have an uneasiness about sleep following any kind of head injury—even a relatively mild one—it’s in your best interest to chat with a healthcare provider, too. “A medical professional can weigh in as to whether your sleepiness is normal or if it’s representative of a progressing brain injury,” Dr. Lumba-Brown said.
Of course, preventing TBIs in the first place is important, too, Dr. Lumba-Brown said. Preventive measures can include always wearing a seatbelt in a vehicle and a helmet when you’re supposed to (like when riding a bike, skiing, or skateboarding). At home, you can also keep walkways clear, clean up spills when they happen, don’t put loose rugs on the floor, and avoid risky behaviors like standing on chairs and climbing on countertops or ladders—especially when you’re alone.