A concussion is a mild traumatic brain injury (mTBI) resulting from a jolt or blow that causes the brain to move rapidly within the skull. This physical trauma triggers a complex chain reaction that temporarily alters normal brain function. A common complaint following this injury is a severe disturbance to sleep patterns. Approximately 30 to 70 percent of concussed individuals report issues, including difficulty falling asleep, staying asleep, or experiencing non-restorative rest. This struggle is a direct consequence of the physiological chaos induced by the injury.
How Concussions Disrupt the Brain’s Sleep Cycle
The inability to sleep often stems from a significant metabolic and neurochemical disruption in the brain following the injury. The initial impact causes a rapid, uncontrolled release of excitatory neurotransmitters, such as glutamate, leading to a cascade of events. This chemical surge causes an ionic imbalance, where potassium ions flood out of the cells while calcium and sodium ions rush in. The brain must then work frantically to restore this balance, which depletes its primary energy source, adenosine triphosphate (ATP).
This massive cellular effort creates a temporary energy crisis, defined as a mismatch between the brain’s high energy demand and its reduced cerebral blood flow and glucose supply. The brain is essentially in a state of exhaustion, yet it lacks the energy reserves required to efficiently enter and sustain the deep, restorative stages of sleep. The physical trauma can also cause axonal shearing, where the brain’s internal wiring is stretched or damaged, further disrupting the normal signaling pathways that regulate sleep and wakefulness.
The trauma directly affects the delicate neurochemical system that controls the sleep-wake cycle, known as the circadian rhythm. Key neuromodulators responsible for promoting wakefulness, such as Orexin/Hypocretin, are vulnerable to post-concussion changes. The overall neurochemical storm—which includes reduced melatonin production and an altered balance of GABA (which promotes sleep) and glutamate—can result in fragmented, poor-quality sleep and insomnia. This combination of metabolic strain, structural damage, and dysregulated chemicals makes it difficult for the brain to “switch off” and achieve the restful state it needs for healing.
The Critical Safety Question: Is It Safe to Sleep?
The immediate concern for many people after a head injury is the outdated notion that a person must be kept awake. This historical warning primarily addressed the risk of a severe traumatic brain injury (TBI) involving a dangerous hematoma, or brain bleed, which could worsen while the patient was unmonitored. However, this advice is now considered a myth for the vast majority of mild concussions, which do not involve bleeding. Current medical consensus strongly supports rest and sleep after a concussion, provided the patient does not exhibit warning signs of a serious complication.
Sleep is a fundamental component of the brain’s recovery process, allowing it to perform necessary maintenance and repair functions without the demands of wakefulness. If the injured person is awake, able to hold a conversation, and has been medically evaluated, they should be allowed to sleep. The danger lies not in the act of sleeping, but in sleep masking a rapid deterioration of the patient’s condition.
Immediate emergency medical attention is necessary if any “red flag” symptoms appear, indicating a potentially severe injury. These signs include:
- A headache that worsens dramatically over time
- Repeated vomiting
- Seizures or convulsions
- Slurred speech or profound difficulty waking up
- Weakness or numbness in the limbs
- Unequal pupil sizes or increasing confusion
If these symptoms are absent, rest and sleep are not only safe but encouraged for healing.
Practical Steps for Restoring Sleep
Establishing a consistent sleep routine is effective for managing post-concussion insomnia. The brain thrives on predictability, so going to bed and waking up at the same time every day, even on weekends, helps to reset the disrupted circadian rhythm. If sleep does not come within about 20 minutes, it is better to get out of bed and do a calming activity until sleepiness returns, rather than lying awake and increasing anxiety.
Limiting cognitive and physical exertion before bedtime helps signal to the injured brain that it is time to wind down. Implement a digital detox, avoiding all screens, including phones, tablets, and television, for at least one hour before bed. The blue light emitted by these devices can suppress the natural production of melatonin, a hormone necessary for initiating sleep.
Avoid self-medicating with alcohol, over-the-counter sleep aids, or sedatives. Alcohol, while acting as an initial sedative, severely fragments sleep architecture, reducing restorative rapid eye movement (REM) sleep and delaying recovery. Similarly, prescription sedatives can mask symptom severity and interfere with the brain’s natural healing processes. If insomnia persists beyond the acute recovery phase (typically four weeks), a professional medical consultation is necessary to explore safe and targeted treatments, such as cognitive behavioral therapy for insomnia (CBT-I).