The brain sends and receives nerve signals to your body. It provides cognition, memory, and emotion. But your brain can prove surprisingly susceptible to injuries in an accident. Even minor trauma can damage or kill brain cells.

There are four common types of brain injuries and three levels of severity. Doctors classify brain injuries based on the way the brain tissue gets damaged.

 Four broad types of brain injuries include:

1. Penetrating Brain Injuries

Penetrating brain injuries happen when an object penetrates the brain tissue. The foreign object dissects the brain tissue, disrupting the neural connections in the brain.

The object can also tear blood vessels. The bleeding can deprive brain cells of oxygen.

Penetrating brain injuries often happen due to:

Foreign Objects

A foreign object can enter the head and cause injury. For example, a piece of material from a machine may penetrate the head in a workplace accident.

Your head could fall onto the foreign object. For example, you could get ejected in a motorcycle accident and fall onto a tree branch that penetrates your brain.

Skull Fragments

A blunt force could fracture your skull and push skull fragments into your brain. Skull fragments can cause the same damage as foreign objects, although you might have a lower risk of infection if the force does not break the skin.

2. Blunt Force Brain Injuries

These injuries happen when a force acts on the brain without penetrating the brain tissue. The force might impact the head, causing head trauma and brain injuries.

The force might also get transmitted to the brain through the neck. For example, the head might get shaken or whipped in a car accident. An accident victim might suffer a brain injury even though nothing impacted their head.

Blunt force brain injuries include:

Concussions

A concussion happens when the brain sloshes around inside the fluid that fills the skull. The motion of the brain creates a pressure wave created in the fluid. This pressure wave causes serious, but non-fatal brain damage.

Most concussion symptoms clear up in six to eight weeks. Symptoms that last longer than two months might signal the presence of post-concussion syndrome.

Contusions

A contusion happens when your brain hits the inside of your skull. Blood vessels inside the brain rupture, and the resulting bruise causes the brain to swell.

Doctors treat contusions as serious injuries because the swelling can cause permanent brain damage, coma, or even death.

Diffuse Axonal Injuries (DAI)

A DAI happens when the whipping motion of the brain tears neurons in the brain called axons.

DAIs cause the symptoms of shaken baby syndrome. DAIs can also accompany whiplash.

3. Anoxic Brain Injuries

Anoxic brain injuries happen when trauma cuts off the brain’s oxygen supply. Hypoxic brain injuries happen when the brain’s oxygen supply drops.

These injuries can happen from:

Permanent brain damage can occur when the brain is deprived of oxygen for just four minutes. Brain death can happen in about ten minutes.

4. Stroke-Related Brain Injuries

Many strokes happen naturally. But strokes can also result from trauma. Bruises, cuts, and broken bones develop blood clots as part of the body’s emergency response. Pieces of these clots can break off and travel to the brain.

There, the clots can become lodged in the blood vessels, depriving the brain of oxygen.

Severity of Brain Injuries

Doctors classify brain injuries as mild, moderate, and severe. Doctors describe any brain injury that causes you to lose consciousness as severe.

Moderate brain injuries disrupt your conscious thinking so you can only:

  • Open your eyes in response to stimulus
  • Move your body in response to pain
  • Answer questions incoherently

You have a mild brain injury if you retain your ability to answer questions and consciously control the opening of your eyes and movement of your body.

Understanding the severity of your brain injury will help doctors identify the level of damage to your brain and provide a treatment plan.