How Does Trauma Affect The Brain And Body?

Trauma comes in many shapes and forms. It can include anything from physical injuries to stressful situations. Examples include car accidents, natural disasters, and dealing with the death of a loved one.

Physical trauma is more common than you think. It’s the top cause of death for Americans between the ages 1 and 44, even more than cancer and heart disease.1 Worldwide, it makes up 10 percent of deaths and 16 percent of disabilities, according to the World Health Organization.2


Even mental health can take a hit. But unlike physical trauma, psychological trauma can develop with or without an injury. All it takes is a dangerous or life-threatening experience.3

When trauma happens, it may affect the body in these seven ways.


1. Stress Response

Trauma initiates stress response

There’s no doubt that trauma is stressful. The second it happens, the stress response kicks into gear.


At first, the fight-or-flight response sparks the defense mode. It can save your life! However, if that stress persists, it can lead to health problems like headaches, insomnia, and digestive issues.4

Over time, chronic stress can snowball into more serious conditions. Heart disease, high blood pressure, and obesity are just some of the possibilities. Immunity can also take a nosedive, increasing the chances for colds and infections.


Emotionally, people feel traumatic stress in different ways. It’s associated with sadness, anger, and irritability. Some people might develop post-traumatic stress disorder (PTSD).5

2. Inflammation

Stress during trauma leads to inflammation


If you want to understand how trauma affects the body, focus on inflammation. This protective response, which is caused by stress, aims to repair the body. Both healing and complications are driven by the inflammatory response.6

Within 30 minutes of a severe injury, inflammation gets to work. It activates platelets to promote clotting, in hopes of stopping blood loss. Inflammatory mediators are also released to alert the immune system. In turn, white blood cells rush to the injury, working to destroy harmful pathogens.


At the same time, inflammation hurts healthy tissue. As the inflammatory mediators move toward the injury, they’re “taken up” by nearby organs. This process can lead to organ damage, causing even more problems.7

3. Impaired Immune System

Trauma can damage the immune system


Trauma can significantly dampen the immune system. It’s all thanks to the inflammation response, which disrupts the immunity’s balance and resistance to infection.

Much of this imbalance is caused by tissue damage. As white blood cells rush to the injury, harmful cell debris is released. The immune system is also exposed to antigens called alarmins. These molecules work to alert the immune response, but can also stress it out.8

Even psychological trauma can suppress the immune system. When the brain is stressed, hormones like cortisol are released. Over time, those hormones can reduce the body’s normal functions and diminish immunity.9

4. Increased Sepsis Risk

Trauma can increase risk for sepsis

When the immunity is severely impaired, a response to infection can lead to widespread inflammation. This life-threatening condition is called sepsis. In the surgical intensive care unit, it’s a major cause of death. Between 28 and 50 percent of patients pass away.

Usually, this body-wide infection is caused by bacteria. But it can also stem from fungi and viruses, and sometimes even localized infections. And since sepsis side effects are similar to other conditions, it can be hard to diagnose. Symptoms include fever, chills, confusion, and fast heart rate.10

5. Poor Blood Flow

Trauma causes problems with blood flow

Sepsis also affects blood flow. The inflammation causes blood clots and leaky vessels, depriving the organs of oxygen and nutrients. As a result, the organs are damaged. Severe cases can lead to multi-organ failure and death.11

Problems with blood flow can develop without sepsis. Both heavy external or internal bleeding can make the body go into shock. This life-threatening condition also deprives the organs of oxygen and nutrients, boosting the risk for multi-organ failure. Common symptoms include anxiety, chest pain, confusion, shallow breathing, and unconsciousness.12

Additionally, when the body gets injured, blood is redirected to the brain and hurt. It can also prevent organs from getting the blood that they need.13

6. Respiratory Damage

Trauma affects the respiratory organs

Often, respiratory organs are the most affected, leading to a condition called acute respiratory distress syndrome (ARDS). It’s responsible for 50 to 80 percent of deaths, making it one of the most serious side effects of trauma. ARDS is also linked to longer hospital stays and worse long-term health.14

Unsurprisingly, patients above the age of 65 years have the greatest risk for ARDS.15

7. Mental Health Issues

Trauma affects mental health

Trauma also affects mental and emotional health. After all, it can be difficult to forget a shocking event, whether it’s an injury or the death of a loved one.

Common symptoms include anxiety, sadness, reduced focus, and trouble sleeping.16 Typically, the sting of a traumatic event decreases in time. Yet, in some cases, a person might find it hard to go back to their normal routine. Flashbacks, erratic emotions and bad dreams can mess with relationships and everyday life.17

Even memory can be affected by trauma. When extreme stress leads to inflammation, neurons in the brain die. Plus, cytokines are highly expressed in the hippocampus, the part of the brain that’s in charge of memory.18

Obviously, the exact effects of trauma depend on the type and severity. It’s also different for each person. From a doctor’s standpoint, this is exactly why trauma can be so difficult to treat.