Whether or not a serious injury can result hitting your head on a car door depends on your age.

We’re talking about casually getting in and out of the vehicle, rather than having one’s head shoved into it by an angry mugger.

It also depends on how you define “serious.” Bleeding in the brain sounds like a very serious injury.

However, when an injury is corrected with a 15-20 minute bedside procedure, it doesn’t sound so “serious.”

How serious can getting hit in the head  by the car door ever be?

In elderly people, it can cause bleeding in the brain—a condition called chronic subdural hematoma.

This condition can sometimes spontaneously resolve, and in other cases, is treated with a 15-20 minute draining procedure.

Chronic subdural hematoma. Credit: Lucien Monfils

“CSDHs often occur in the elderly after a trivial injury without any damage to the underlying brain,” says a report in the Postgraduate Medical Journal (2002).

An acute subdural hematoma “generally occur in younger adults, after a major trauma,” says the PMJ.

Examples: vehicular accident, skiing accident, being thrown from a horse.

So for a person under 50, hitting one’s head against the car door frame while getting into the vehicle or exiting it does not constitute a major trauma.

Sure, it hurts, but did anything ever come of it? Not if you’re young.

For younger people, “You would have to hit yourself REALLY hard to do enough damage to cause serious brain injury, and most of us — even when we do hit ourselves in that way — only have a minor blow to the head,” explains Susan L. Besser, MD, with Mercy Medical Center, Baltimore, and Diplomate American Board of Obesity Medicine and board certified by the American Board of Family Medicine.

So why can getting one’s head bonked by the car door frame be more serious for an elderly person?

• The brain shrinks with age.

• This creates more space between the brain and skull.

• “This causes stretching of the bridging veins, and the greater movement of the brain within the cranium makes these veins vulnerable to trauma,” says the PMJ.

• Tiny tears occur to the veins.

• The tears are so small that the bleeding is very slow (chronic), and symptoms typically take several weeks to a few months to begin appearing.

With an acute subdural hematoma, such as that caused by getting one’s head slammed through the windshield in a car accident, or repeatedly pummeled in a boxing match, the bleeding occurs within 72 hours and is very life-threatening.

The bigger size of a younger adult’s brain provides a tight fit against the skull, better protecting the bridging veins from tears resulting from trivial bangs to the head.

NOTE: A young person with a pre-existing aneurysm can sustain what appears to be a minor bang to the head — but it may be enough to cause the aneurysm to rupture, requiring immediate medical intervention.

This article pertains to the typical individual and subdural hematomas, which involve torn veins, not arteries.

ER doctors are not surprised when a CT scan of an elderly person shows a chronic subdural hematoma.

When asked if they’d hit their head in the past several weeks, 50-70% report yes, says the PMJ.

“About half the patients have a history of fall but without hitting their head on the ground.”

The whiplash movement of an elderly person’s head from a fall, even though the head never strikes the ground, is enough to jar the brain and tear the veins.

Also, an actual hit to the head may have been so trite that the patient can’t even remember that it ever happened, such as hitting their head against the car door frame seven weeks ago.

What makes an incident like this even more potentially serious to senior citizens is that many are on blood thinners.

Up to 24 percent of cSDH patients are on the blood thinner Warfarin (coumadin) or some other antiplatelet drug.

Middle aged or younger adults, after hitting their head hard on the car door, may become quite unnerved over the possibility of a brain bleed.

They don’t know about chronic subdural hematoma, and perhaps ONLY know about acute subdural hematoma.

When I was 21 I was flipped to the floor (hard mat) in a judo class, getting the back of my head slammed pretty good.

For the next few weeks I feared a “subdural hematoma.” I didn’t know about acute vs. chronic.

Even after three weeks, I was still fearful that any moment blood would start gushing out somewhere in my brain.

After three weeks without incident, I decided that if something bad were going to happen, it would have happened already.

What I didn’t know was that when bleeding begins occurring during the “chronic” phase (three+ weeks out from the incident), you have time to get to the hospital – it’s not one of those screaming ambulance emergencies.

In fact, when my mother in her 80s passed out in the bathroom and slammed her head on the porcelain bathtub, her CT scan later that day was normal. She was fine for six weeks.

Then she awakened with the worst headache ever and weakness in both legs. A new CT scan showed a chronic subdural hematoma.

However…the brief drainage procedure was scheduled for the next morning!


Non-elderly adults are at much lower risk for a brain bleed from minor bangs to the head; in typical younger adults they are extremely rare.

As much as getting hit by the car door frame hurts…it’s minor when compared to getting one’s head slammed into a tree while skiing, or slammed to concrete from a skateboard trick gone wrong, or falling off a ladder.

Dr. Besser provides comprehensive family care, treating common and acute primary conditions like diabetes and hypertension. Her ongoing approach allows her the opportunity to provide accurate and critical diagnoses of more complex conditions and disorders.
Lorra Garrick has been covering medical, fitness and cybersecurity topics for many years, having written thousands of articles for print magazines and websites, including as a ghostwriter. She’s also a former ACE-certified personal trainer.  


Top image: Shutterstock/wavebreakmedia
Source: pmj.bmj.com/content/postgradmedj/78/916/71.full.pdf

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