How Does Anxiety Affect the Brain?

Anxiety is more than just a mental or emotional experience—it has real, measurable effects on the brain. 

If you’ve ever wondered, “How does anxiety affect the brain?”, “What does anxiety look like in the brain?” or “Does anxiety change your brain?”, you’re not alone. 

Ongoing stress and worry can change brain structure, disrupt cognitive processes, and even influence how we manage emotions. Anxiety and the nervous system are also interlinked, meaning you can also find it harder to relax.

In this article, we’ll explore how anxiety affects the brain, the specific regions involved, five major effects, and what to know about long-term consequences.

How Does Anxiety Affect the Brain?

What can anxiety do to your brain? Anxiety affects the brain by activating its fear and stress response systems. This includes triggering areas like the amygdala, which processes threats, and the hypothalamus, which initiates the body’s fight-or-flight response. 

When anxiety becomes chronic, these systems stay on high alert, leading to changes in brain chemistry and structure. Over time, this constant activation can affect memory, decision-making, and emotional regulation.

What Does Anxiety Do to Your Brain? 4 Effects of Anxiety on the Brain

Anxiety and the brain are interlinked. Let’s look at what anxiety does to the brain in closer detail.

1. Hyperactivity in the amygdala

The amygdala is a small, almond-shaped structure deep in the brain that plays a key role in processing emotions, especially fear and danger. In people with anxiety, the amygdala becomes hyperactive, even when there’s no real threat present. This overactivation causes the brain to remain on constant alert, interpreting neutral or minor events as dangerous.

As a result, you may find yourself startled easily, overly sensitive to criticism, or constantly bracing for the worst. The heightened fear response also makes it more difficult to calm down after a stressful experience, which can fuel a cycle of ongoing anxiety.

2. Reduced volume in the hippocampus

The hippocampus is vital for learning and forming new memories. Studies have shown that chronic anxiety and high stress levels can cause this area of the brain to shrink in volume.

A brain with anxiety means that the hippocampus is affected, meaning it becomes harder to retain information, concentrate on tasks, or recall things when needed. This is one reason people with anxiety often report feeling forgetful or mentally “foggy.” Over time, these cognitive challenges can impact academic performance, work productivity, and everyday decision-making.

3. Increased cortisol and stress hormones

When you’re anxious, your brain signals the release of cortisol, the body’s primary stress hormone. Cortisol is helpful in short bursts—it prepares you to respond to immediate danger by increasing alertness and energy. But when anxiety is chronic, cortisol levels stay elevated for too long.

Prolonged exposure to high cortisol can lead to inflammation in the brain, impair memory, reduce immune function, and disturb sleep cycles. You may feel physically and mentally drained, have trouble falling asleep or staying asleep, and become more prone to mood swings and fatigue. Over time, this hormonal imbalance increases the risk of developing depression and other health issues.

4. Mood and neurotransmitter imbalance

Anxiety alters the delicate balance of neurotransmitters in the brain—chemical messengers that regulate mood, motivation, and relaxation. Key players like serotonin (linked to mood and well-being), dopamine (reward and motivation), and GABA (calming effects) often become imbalanced in individuals with chronic anxiety.

When these brain chemicals are out of sync, it becomes harder to experience pleasure, feel motivated, or stay emotionally stable. This imbalance contributes to the emotional symptoms of anxiety, such as irritability, sadness, and low energy. It can also open the door to co-occurring mental health disorders like panic disorder, obsessive-compulsive disorder (OCD), and depression.

What Part of the Brain Does Anxiety Affect?

The effects of anxiety in the brain are primarily found in three areas of the brain:

• Amygdala – Triggers fear and emotional reactions. Overactivity can make threats seem bigger than they are.
  
• Hippocampus – Handles memory and learning. Chronic anxiety can reduce its size and efficiency.
  
• Prefrontal cortex – Responsible for logical thinking and self-control. Anxiety can reduce activity in this area, weakening your ability to manage fears rationally.
  

These areas don’t work in isolation—when one is out of balance, the others are often affected too, creating a feedback loop that reinforces anxiety.

Need Professional Help With Anxiety?

If anxiety is interfering with your daily life, relationships, or health, it’s time to seek support. Therapy, medication, or a combination of both can help rebalance your brain and teach you tools to manage symptoms. Talking to a mental health professional is a strong first step toward feeling better and protecting your brain long-term.

Wondering how to talk to your doctor about anxiety? At Brightside Health, we take a personalized, evidence-based approach to treating anxiety and panic disorders. 

Our licensed providers specialize in matching each individual with the right medication and care plan based on their unique symptoms, preferences, and treatment goals. 

With online access to therapy, medication management, and ongoing support, Brightside makes it easier than ever to get help from anywhere. 

Take the anxiety test to discover how anxiety is interfering with your daily life and what you can do about it.

Key Takeaways

Anxiety isn’t just a feeling—it actively changes how your brain works. 

How does anxiety work in the brain? From increased amygdala activity to reduced memory function in the hippocampus, anxiety can impact both your emotional and cognitive health. 

These changes can lead to ongoing stress, difficulty concentrating, and mood problems. 

The most important point: anxiety is treatable, and getting help can prevent or reverse many of these brain-related effects.

FAQs

What happens in the brain during anxiety?

During anxiety, the brain activates its threat response system. The amygdala signals danger, while the hypothalamus triggers stress hormones like cortisol. This makes you feel on edge, hyper-alert, and physically tense.

Anxiety also temporarily reduces activity in the logical parts of the brain (prefrontal cortex), making it harder to think clearly during stressful situations.

How are anxiety effects on the brain measured?

Researchers use brain imaging techniques like MRI and PET scans to observe changes in brain structure and activity. These tools show differences in volume, blood flow, and connectivity in anxiety-affected brains compared to healthy ones.

In clinical settings, changes in thinking, memory, and mood can also be evaluated through psychological tests and symptom assessments.

What are the long-term effects of anxiety on the brain?

Long-term anxiety can lead to reduced brain volume in key areas like the hippocampus, disrupted emotional regulation, and memory problems. It also increases the risk of developing mood disorders and cognitive decline over time.

If untreated, chronic anxiety can worsen physical health as well, affecting sleep, heart health, and immune function.

How does anxiety affect the nervous system?

The nervous system and anxiety are interlinked. Anxiety keeps your sympathetic nervous system activated, which controls the fight-or-flight response. This constant activation can wear down the body and make you feel jittery, tense, or exhausted.

It also reduces the function of the parasympathetic nervous system—the part that helps you rest and recover, making it harder to relax.

Can anxiety make you emotional?

Yes. Anxiety can heighten emotional responses, making you more sensitive, irritable, or overwhelmed. It can also make it harder to manage frustration or sadness.

This happens because anxiety affects both the emotional (amygdala) and logical (prefrontal cortex) areas of the brain, making emotions feel more intense and harder to control.

Can anxiety damage the brain?

Prolonged anxiety can potentially lead to structural changes in the brain, especially if left untreated. High cortisol levels over time can shrink parts of the brain, impair memory, and increase the risk of mood disorders.

However, with treatment and stress management, many of these effects can be reversed or prevented.

What is anxiety brain fog?

Anxiety brain fog refers to the mental cloudiness or lack of focus that often accompanies anxiety. You may feel forgetful, easily distracted, or like your mind is “offline.”

It’s often caused by overstimulation of the brain’s fear centers and the draining effect of chronic worry, leaving little energy for concentration and mental clarity.