Concussion: why is it dangerous?

Medically reviewed: 15, February 2024

Read Time:10 Minute

Definition of Concussion

A concussion is a closed head injury that causes headaches, dizziness, nausea and vomiting.

The brain is the main organ of the nervous system, controlling the functioning of the entire body. It is protected by the shell of the skull, as well as the hard and soft shells, between which there is cerebrospinal fluid (CSF). It mitigates brain damage from head impacts.

Despite such protection, the percentage of brain injuries remains quite high. The leading position among them is concussion.

A concussion is not very dangerous compared to other skull injuries, as symptoms subside after 2-3 weeks.

Causes of concussion

The cause of such an injury can be a fall, a street fight, a traffic accident, or playing certain sports (boxing, hockey, football, figure skating, etc.).

Risk factors also include neglect of safety rules, old age and childhood.

If you notice similar symptoms, consult your doctor. Do not self-medicate – it is dangerous for your health!

Symptoms of a concussion

The leading symptom of a concussion is loss of consciousness. Moreover, the longer the patient is unconscious, the more severe the concussion. Usually a person comes to his senses within 10 minutes.

Another important sign that helps determine the severity of the injury is memory loss. There are three types of so-called amnesia:

  • retrograde – the victim does not remember what happened a few minutes or months before the injury;
  • congrade – the victim does not remember part or all of the events that occurred during the acute period of the disease;
  • anterograde – after injury, the patient loses the ability to remember events.

After treatment, memory is restored. First, the most vivid emotional impressions return; over time, smaller details are also restored. The time and extent of memory recovery depends on the severity of the injury, as well as some other factors, such as the state of memory before the injury.

First symptoms of Concussion

After the patient regains consciousness, the following symptoms appear:

  • pressing pain in the head;
  • dizziness, which intensifies when changing body position;
  • confusion, decreased attention, rapid mood swings (may occur later), sometimes disorientation in time and space;
  • blurred vision, blurriness, diplopia (split objects);
  • nystagmus (rhythmic eye movements);
  • tinnitus;
  • slurred speech;
  • inhibition of actions;
  • nausea, vomiting;
  • photo- and phonophobia (increased sensitivity to light and sound);
  • rapid change in skin color from bright red to pale, weakness, sweating;
  • fluctuations in heart rate and blood pressure;
  • temperature rise to 37.5 °C.
  • nystagmus

Delayed symptoms of Concussion

Delayed symptoms occur a few days after the injury or earlier:

  • drowsiness, increased fatigue;
  • irritability, anxiety with the possible development of an episode of depression (constant fatigue, apathy and melancholy);
  • bad dream.

Symptoms can appear together or separately.

Often the clinical picture of a concussion depends on the age of the victim. For example, infants with traumatic brain injury usually do not lose consciousness. In such cases, you should pay attention to pale facial skin, lethargy, restless sleep, vomiting and/or regurgitation after eating. The condition improves after 2–3 days. In preschool children, as well as in older people, the symptoms are blurred, so sometimes loss of consciousness can go unnoticed.

Any traumatic brain injury requires treatment, so after a concussion, regardless of the severity of the symptoms, it is necessary to consult a traumatologist.

Pathogenesis of Concussion

Several theories play a role in the mechanism of development of traumatic brain injury. For example, there is a theory in which the main importance is given to metabolic disorders, due to which the activity of neuronal membranes is disrupted. This leads to damage to nerve fibers and ultimately disrupts the central nervous system, followed by concussion symptoms.

This theory was confirmed by experimental modeling of traumatic brain injury in laboratory animals.

However, the following can be considered the most common: pressure gradient theory and rotation theory.

Pressure gradient theory

When there is a blow or injury to the head, deformation of the skull develops, after which intracranial pressure increases, the brain is displaced and movement inside the skull accelerates. In this case, the pressure increases on the side of the impact, and on the opposite side, on the contrary, decreases. This causes cavities and small gas bubbles to form in the brain tissue.

The negative pressure lasts a thousandth of a second, and the bubbles also quickly regress. An imbalance between the pressure in the vessels and in the surrounding brain tissue damages the capillaries and brain structures. A so-called cavitation process occurs, which causes the appearance of symptoms of a concussion.

This theory is the most common.

Rotation theory

It was confirmed in an experiment. It was found that when the head is hit or bruised simultaneously in 2-3 planes, the moving parts of the brain begin to rotate, and the fixed brain stem parts become twisted. In this case, some areas of the brain are displaced relative to each other. All this damages synapses, nerve fibers and blood vessels in the brain, which leads to the development of concussion symptoms, including delayed ones.

Classification and stages of development of concussion

Mild traumatic brain injury is divided into several degrees:

  1. mild degree – occurs without loss of consciousness and memory, with slight nausea, symptoms disappear within half an hour;
  2. moderate degree – manifested by moderate nausea, periodic headaches, dizziness, staggering when walking and photophobia (unpleasant feeling when looking at bright light);
  3. severe degree – characterized by loss of consciousness for up to 10 minutes, pronounced memory loss, severe headaches, dizziness, photophobia, unsteadiness of gait, nausea, repeated vomiting and lethargy.

Complications of a concussion

All consequences of traumatic brain injury can be divided into transient (short-term) and long-term disorders.

Transient include all symptoms that have not gone away a month after receiving a head injury. These are headaches, dizziness, staggering when walking, weakness, fatigue, increased sweating, decreased mood or mood swings, tearfulness, irritability, poor sleep.

Long-term consequences that can develop several months and even years after a traumatic brain injury include:

  • Post-traumatic epilepsy – manifested by loss of consciousness, convulsions, tongue biting, foam at the mouth and loss of urine. The risk of developing post-traumatic epilepsy depends on the severity of the traumatic brain injury and the presence of repeated concussions.
  • Postconcussion syndrome – accompanied by fatigue, irritability, dizziness, headache and apathy. Symptoms intensify against the background of psycho-emotional stress and improper daily routine.
  • Second impact syndrome is swelling of the brain. Appears after repeated traumatic brain injury, when the symptoms of the first have not yet passed. It manifests itself as headaches, dizziness, speech impairment, nausea and vomiting, which do not bring relief, decreased visual acuity, convulsions and loss of consciousness of varying degrees, up to deep coma. Cerebral edema is an emergency and requires emergency hospitalization.
  • Intracranial hypertension syndrome – manifested by pressing headaches, nausea and vomiting. These symptoms occur daily, maybe several times a day. Sometimes they get worse due to changes in weather and overwork.
  • Personality changes – tearfulness, irritability, rapid mood swings. Usually such changes are noticed by others, but in severe cases the patient may also pay attention to this.

Memory usually recovers within a few weeks or months, depending on the injury. However, in some cases, memory problems remain. Such patients require repeated treatment. Ultimately, 80% of them return to their previous level within six months, the rest have to change their type of activity or reduce the number of working hours.

Diagnosis of concussion

A concussion is diagnosed based on complaints and neurological examination data.

When contacting a doctor, you should explain in detail the circumstances of the injury, the mechanism of its occurrence, and also describe the complaints. This will help the doctor quickly make the correct diagnosis and begin treatment earlier.

In the first hours after a concussion, the pupils greatly constrict or dilate, and the reaction to light also worsens. A complete lack of response indicates severe brain damage.

When examining the pupils, pay attention to anisocoria (difference in diameter), which can also indicate the side of the lesion. For example, if the left pupil is damaged, then the work of the right hemisphere is disrupted, and vice versa.

Differential diagnosis of concussion

Differential diagnosis is based on the patient’s complaints, medical history, examination data, laboratory and instrumental studies.

In case of a concussion, it is important to exclude other, more severe injuries to the skull:

  • post-traumatic subdural hematoma;
  • hemorrhage into the subarachnoid (subarachnoid) space;
  • fractures of the skull bones.

If a concussion is suspected, the following tests should be performed:

  • general blood and urine analysis – carried out if the temperature has risen to exclude other causes of its occurrence;
  • craniography (x-ray of the skull) in two projections – excludes bone-traumatic changes.

Additionally you may need:

  • echoencephaloscopy – allows one to suspect an intracerebral hematoma;
  • computed tomography (CT) of the brain – carried out according to indications for severe concussion, its results exclude fractures of the skull bones, intracerebral hematomas and post-traumatic hemorrhages in the brain;
  • consultation with an ophthalmologist – conducts an examination of the fundus.

If necessary, the patient is consulted by other specialists: a therapist examines a victim with hypertension or coronary heart disease, a surgeon or traumatologist if there is a suspicion of internal organ injury and fractures.

Treatment of concussion

Even with a mild concussion, hospitalization in the trauma department is necessary. This allows you to increase the effectiveness of treatment and improve the prognosis. Inpatient treatment lasts five days, after which the patient undergoes outpatient treatment with a neurologist.

Non-drug treatment

In the hospital, the patient is on bed rest. The victim can turn over in bed, sit on the bed with his legs dangling, perform morning and evening toilets, eat in bed, but he should not read books, use a mobile phone or computer, listen to loud music or watch TV. If the patient does not comply with the ban, the symptoms intensify and the recovery period is delayed.

During treatment, the patient must avoid drinking alcohol, coffee, strong tea and energy drinks. At the same time, the diet must include buckwheat, beans, eggs, liver, i.e., products containing B vitamins. It is also advisable to replace bread made from premium flour with bread made from whole grain flour. It is necessary to maintain a strict balance between carbohydrates, fats and proteins. The average formula for the ratio of proteins, fats, carbohydrates looks like this:

  • proteins – 15–20%;
  • fats – 30%;
  • carbohydrates – 55–60%.

Drug treatment

Medicines prescribed for the treatment of concussion are divided into basic and additional.

The main ones include:

  • painkillers – non-steroidal anti-inflammatory drugs, other non-narcotic analgesics;
  • drugs that stimulate microcirculation and permeability of the capillaries of the inner ear, as well as drugs that stabilize the pressure of the endolymph in the cochlea and labyrinth of the ear – prescribed for dizziness;
  • dehydrating drugs – against edema, used for three days.


  • vascular and metabolic drugs – the method of administration depends on the severity of the victim’s condition;
  • antiemetics.

Prevention of concussion

If you follow all the recommendations of your doctor, the probability of a favorable prognosis is 90%. In other cases, memory problems and sudden changes in mood persist, which also disappear over time.

The prognosis also depends on the severity of the injury and other factors, including the duration of loss of consciousness.

In case of a traumatic brain injury, it is important to immediately consult a doctor, undergo the prescribed course of treatment and be observed by a neurologist for a year to reduce the risk of possible complications.

To prevent a concussion, you must follow these rules:

  • wear protective equipment when engaging in extreme sports and horseback riding;
  • follow safety rules while driving a car – do not drive after taking alcohol and sedatives that slow down the reaction rate, use a seat belt, transport children in special child seats;
  • be careful at home – buy non-slip house shoes, promptly wipe up liquid spilled on the floor;
  • be careful when walking, especially in winter – use anti-slip devices for shoes (various pads and stickers).

This article is written by

Lucas Harrington - traumatologist
Lucas Harrington - traumatologist

Leave a Reply

Your email address will not be published. Required fields are marked *