
By Natalie Dale, MD
As a former physician, I get a lot of questions from other writers about medical aspects of their stories. And while every story is unique, there are a few mistakes writers seem to make over and over. Below are three of the most common mistakes, along with suggestions on how to avoid them.
1. Passing Out from Blood Loss
The mistake:
Your character is injured in a fight and they’re losing blood, fast. Then the world goes black. They wake up some time later, woozy but otherwise fine, with a bandage slapped over the wound.
Why it’s wrong:
If your character is bleeding out fast enough to pass out, they’re bleeding out fast enough to die. The average human contains about five liters (5L) of blood. The amount of blood they lose, and how fast they lose it, will dictate their symptoms.
- 10% blood loss (0.5L): Minimal symptoms
- 20% blood loss (1L): Anxiety, dizziness, and blacking out when going from lying down to standing up (called orthostatic hypotension)
- 30% blood loss (1.5L): Low blood pressure, racing pulse, and fast breathing rate, feeling woozy/drowsy, having difficulty focusing. Also called hemorrhagic shock.
- 40% blood loss (2L): Loss of consciousness
- 50% blood loss (2.5L): Death

It doesn’t take much to go from unconscious to dead. If you want your character to pass out from blood loss—and survive—they’ll need some sort of intervention to stop the bleeding. And no, slapping a bandage over the wound won’t cut it.
How to fix it:
Get your character medical care, such as surgery, blood products, and pressors, soon after they fall unconscious. If that isn’t possible, consider having them pass out from pain or from the sight of their own blood, rather than from the blood loss itself.
2. The Harmless Head Injury
The mistake:
Your protagonist has subdued her nemesis; all she must do now is get rid of him. But she’s the good guy—she can’t kill him. So, she knocks him unconscious instead. He wakes up an hour or so later with a mild headache and a burning desire for vengeance.
Why it’s wrong:
A hit to the head that causes unconsciousness is a traumatic brain injury, or TBI. TBIs are major injuries, with lasting consequences ranging from daily headaches to coma and death. Here’s a brief guide to the symptoms your character should exhibit based on the duration of their unconsciousness.
- No loss of consciousness: Mild-moderate concussion. Concussion symptoms include headaches, dizziness, ringing in the ears, trouble concentrating, short-term memory problems (posttraumatic amnesia), and behavior changes that last from several hours to a few weeks.
- Brief loss of consciousness (seconds to 30 minutes): Severe concussion or epidural hematoma, a potentially fatal type of brain bleed. If your character has a concussion, they will have severe concussive symptoms (see above) lasting days to months. If they have an epidural hematoma, your character will briefly pass out, then wake up and insist they’re fine. But watch out! As they continue to bleed into the space between their brain and skull, your character will get progressively drowsier and more incoherent, until they fall asleep. If they don’t get neurosurgery to stop the bleed, they’ll die.
- Up to 6 hours unconscious: Moderate TBI. Requires hospitalization and often ICU admission. After their hospitalization, your character will require weeks to months of intensive rehabilitation to recover. If your character doesn’t receive treatment, they may die.
- More than 6 hours unconscious: Severe TBI. Your character will require treatment in the ICU. If they survive—and many don’t—they will probably suffer from lifelong disability. Full recovery from a severe TBI is exceedingly rare.
How to fix it:
Unfortunately, there is no safe way to instantaneously knock someone unconscious, keep them unconscious for any appreciable amount of time, then have them wake up and be totally fine. It’s a buzzkill, I know. But there are ways you can make it work.
- Hit them over the head and give them a concussion: If your story needs your character to be immediately knocked unconscious for a few minutes, you can get away with it. Just keep the duration of unconsciousness to under 30 minutes and give them signs of a concussion afterwards.
- Give a sedative: If your story needs a character to be knocked out for a while, consider giving them a sedative like midazolam (Versed). Intravenous (IV) administration would start working fastest but can’t be given quickly. Intramuscular (IM) injections, on the other hand, can be given in as little as 2-4 seconds. Because they’re so easy to give, IM sedatives are often used by paramedics and psychiatrists on severely agitated patients. Once injected, these medications will take 15-30 min to take effect, but once it does, the character will be reliably asleep for up to 90 minutes.
3. The Mythical “Medically Induced” Coma
The mistake:
Your character has been grievously injured, so they are put in a medically induced coma to heal. They’re on the brink of death and the family/police can’t talk to them, so no one really knows what happened. All they can do is wait and pray your character will be OK.
Why it’s wrong:
People aren’t put into comas to heal. In fact, therapeutic comas (the medical term for “medically-induced coma”) are used only in two very specific situations. But first, let’s talk definitions.
A coma is a prolonged state of unresponsiveness, meaning that your character isn’t responding at all to their environment. Coma isn’t a diagnosis; there are lots of things that can cause a coma, ranging from drug overdose to TBI. If your character is in a coma, it means their brain has suffered a big enough insult that it needed to shut down some of its most basic functions. The prognosis of a coma depends on both its cause and duration. But for the most part, if your character is in a coma, they are going to have a very long road to recovery.
A therapeutic coma is when doctors give your character medications to artificially depress brain function so completely that your character becomes comatose. Doing so is quite dangerous; your character will need to be intubated and put on a ventilator to breathe for them, and their vital signs—particularly blood pressure—will need to be closely monitored. Because it’s so dangerous, your character will only be put into a therapeutic coma if doctors need to shut down all brain activity. And there are only two reasons for this: unrelenting seizures (refractory status epilepticus) and increased pressure inside the skull (increased intracranial pressure) due to brain swelling, bleeding on the brain, or a fast-growing brain tumor. These conditions are exceedingly dangerous and have a terrible prognosis. If you want your character to fully recover from their injuries, I highly recommend avoiding the therapeutic coma.
How to fix it:
Luckily, there is an easy solution: ventilation and sedation.
If your character has been seriously injured, they might need to be put on a ventilator to help them breathe. Reasons for needing a ventilator range from traumatic chest injuries, like flail chest or pulmonary contusion, to pneumonia. Ventilators are notoriously uncomfortable—many people who’ve been on a ventilator get PTSD from the experience—and so ventilated patients are usually kept at least minimally sedated.
Unlike comas, the prognosis of recovery after sedation is excellent. The medications can be reversed or just given time to make their way out of your character’s system, and they’ll wake right up. Ventilation and sedation provide all the tension of a life-threatening injury—and the inability to communicate—without the horrible prognosis of the medically induced coma.
Final Thoughts
What we write matters. Though it may seem like nitpicking to insist that you sedate your character instead of putting them in a medically induced coma, or give your character symptoms of a concussion after their head injury, I assure you that it’s important. There are real people out there suffering from these conditions and how we, as writers, portray these conditions can make a real difference.
Source: writershelpingwriters.net
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