Do you lose brain cells when you hit your head?

When you hit your head, it is natural to worry about brain health. Many wonder if a head impact leads to the loss of brain cells. The answer is yes: a severe blow to the head can damage or destroy brain cells. However, the extent of damage varies widely depending on the force of impact, the location of the injury, and individual factors¹. This article explains how the brain is affected by head trauma and what happens at the cellular level.

What happens in the brain after a head impact?

The brain is protected inside the skull and surrounded by cerebrospinal fluid, which cushions against shock. With a strong blow, however, the brain can move within the skull and collide with the inner bone structure². This may result in:

• Micro-injuries to nerve cells (neurons)

• Tearing of blood vessels, which may cause minor or severe bleeding

• Chemical changes, as sudden release of neurotransmitters disrupts normal cell function

These mechanisms underlie concussions, brain hemorrhages, or more severe traumatic brain injuries.

Do you actually lose brain cells?

In mild cases, such as a simple concussion without loss of consciousness, there is rarely permanent loss of a large number of brain cells³. The brain is capable of repairing minor injuries over time. However, in more severe trauma:

• Neurons may die due to mechanical injury

• Inflammatory processes may worsen the injury and cause secondary cell death

• Reduced blood supply may lead to oxygen deprivation (hypoxia) and cell destruction⁴

In serious head trauma, loss of brain cells can result in lasting neurological problems, including difficulties with concentration, memory loss, or motor impairment.

What determines how severe the injury is?

Several factors influence whether a head impact causes loss of brain cells:

• Force of impact: The stronger the blow, the greater the risk

• Location of impact: Injuries to the forehead or temples can be more dangerous due to brain anatomy

• Age: Older adults and young children have more fragile brain tissue and are more vulnerable

• History of prior injuries: Repeated concussions increase the risk of chronic brain damage, such as chronic traumatic encephalopathy (CTE)⁵

What should you do after hitting your head?

After a significant head impact, be alert for symptoms such as:

• Worsening headache

• Confusion or memory loss

• Nausea, vomiting, or dizziness

• Loss of consciousness, even briefly

If these occur, medical evaluation is essential. Imaging techniques such as CT or MRI may be needed to rule out serious injury.

Can the brain repair itself?

The brain has some ability to adapt and repair damage, especially after mild injuries. This process, known as neuroplasticity, allows other brain regions to compensate for damaged areas. Still, rest is crucial after a head injury. Avoiding further impacts and following medical guidance carefully is important to support optimal recovery.

References

1. McKee AC, et al. The spectrum of disease in chronic traumatic encephalopathy. Brain. 2013.

2. Giza CC, Hovda DA. The neurometabolic cascade of concussion. J Athl Train. 2001.

3. Prins ML, et al. Repetitive mild traumatic brain injury: mechanisms of cerebral vulnerability. J Neurotrauma. 2013.

4. Werner C, Engelhard K. Pathophysiology of traumatic brain injury. Br J Anaesth. 2007.

5. Stein TD, Alvarez VE, McKee AC. Chronic traumatic encephalopathy: A spectrum of neuropathological changes following repetitive brain trauma in athletes and military personnel. Alzheimers Res Ther. 2014.