How does stress affect our brain?


Stress is a very familiar experience that you come across frequently in your daily life. It happens to you almost every day, in a variety of different forms. You might feel stressed about your financial status, work, family, or personal health. If you come across any serious stress threat, your body immediately goes under potential action to dissolve that stress.

Your body can get rid of stress in two different ways- either deal with it (fight) or avoid it (flight). With the terms ‘fight’ and ‘flight’, you might have already guessed the hormone responsible for such emergency actions. Yes, you right. It is the adrenaline hormone that regulates your body during stress. When you have acute stress, your physical state goes through troubles like chest pain and headache. Your emotional wellbeing gets compromised, which is why you feel extremely anxious and depressed. Other behavioral changes may include utter rage, overreaction, and irritability.

However, have you ever wondered what happens inside your brain when you see stress-related symptoms? Stress has a huge impact on your brain cells that makes your brain go through a cascade of reactions. Some reactions are good, while others are worse for mobilizing and protecting your body from possible threats. Stress contributes to adverse effects on your brain, thereby shrinking its volume and result in mental illness.

How physiological stress affects the brain?

When you experience stress, it is not just one event that is happening. Stress triggers a series of cascading reactions in your brain, affecting various parts of your body. When you undergo a stressful event, an area of your brain called the amygdala transmits a distress signal reaching the hypothalamus. Amygdala is majorly responsible for processing your emotions.

Hypothalamus works as a center of command for the brain, to communicate with different regions of your body. This communication mainly relies on your nervous system, so that you get the strength to either fight or flee stress. The emergency ‘flight or fight’ reaction is because of the adrenaline hormone that governs it. When your body secretes adrenaline in increased amounts, it results in-

  • the rise in heart rate
  • alertness
  • improved senses
  • greater uptake of oxygen by your body cells

Due to high adrenaline function, your body releases another hormone called cortisol, to restore the lost energy during emergency response. When you come out of the stressful condition, cortisol levels drop along with adrenaline levels. Your body again comes back to the state of normal homeostasis.

How can chronic stress be a neuronal threat?

Chronic stress majorly refers to the condition where excess cortisol accumulates in your brain. This phenomenon can lead to a number of severe health issues, encompassing synaptic disruptions and malfunctioning immune system. Cortisol is a naturally produced steroid hormone with numerous physiological functions like-

  • Regulating blood glucose levels
  • Reducing inflammation
  • Helping in memory formulation
  • Regulating metabolism
  • Monitoring blood pressure by balancing salt and water ratios in the body
  • Has practical effects on the hippocampus, helping in storing and processing memory

All these normal functions get disturbed when you suffer from chronic stress. Your body starts producing cortisol in greater amounts than it is used up or released. The combination of chronic stress and high cortisol level can prove to be extremely detrimental. Increased cortisol levels deteriorate the normal functioning of brain cells.

Chronic stress can alter neuronal functioning in various ways. It can disrupt the regulation of synapses, which may lead to a condition where you lose sociability. You start to avoid interactions with people as you find it difficult to process multiple views. Too much stress can result in the death of neurons, eventually reducing the volume of your brain. Chronic stress produces a diminishing effect on the brain’s prefrontal cortex, the part responsible for learning and memorizing.

However, if the stress is toxic, it can impair your immunological functions and worsen the condition of existing illnesses. Neuroplasticity can result in serious health disorders, such as heart diseases, diabetes, and elevated blood pressure levels.

What happens to brain structure during stress?

Your brain is composed of several support cells and neurons, functioning together in a nest-like setup. This structure is called the ‘gray matter’, which is responsible for functions like problem-solving and decision making. Another part of the brain called the ‘white matter’ contains axons. They are responsible for passing information in the form of electrical impulses throughout your brain. The name white matter is because of the presence of white colored, fatty myelin sheath surrounding the axons.

When you are under extreme stress, your brain starts producing excess myelin sheath. This causes a disruption in the balance between the gray and white matter. Such an imbalance can further lead to long term effects on your brain structure. When you suffer from post-traumatic stress disorder, you will experience brain abnormalities related to the balance of gray and white matter. Good stress can help you rewire this imbalance, building deeper neuronal networks.

How stress shapes neuroplasticity?

Plasticity of brain cells or neuroplasticity is the ability of neural pathways within your brain to reform. For example, if you are suffering from stress, the neural pathway between amygdala and hippocampus can get seriously compromised. However, such alterations are not meant to be permanent damage. Although the stress can pose negative effects on your brain cells, it is not that your body and brain cannot recover from it.

As you age, the ability of your brain to recover from stress gradually reduces. However, certain ‘interventions’ in your regular lifestyle can revert brain cells to a normal state through ‘wear and tear’. Such ‘interventions’ refer to physical workouts or exercises that you can perform, to strengthen your brain cells for fighting stress. Exercising and staying healthy is regardless of aging of process, and you cannot simply question its effectiveness.

Try socializing with people, indulge in physical activities to improve brain plasticity. Stress is an inescapable component of life, so you cannot simply run away from it. Learn to deal with it using a positive approach and a healthy lifestyle.