Feeling nervous but you don’t know why? We look at why anxiety might arise without a clear cause.

The factors that spark anxiety are different for everyone and can be subtle. Many people are familiar with anxious feelings but don’t know their cause, so it feels like the anxiety is happening for “no reason.”

Everyone gets anxious sometimes, but some people are more prone than others. Possible causes of anxiety can include genetics, stressful situations, previous traumas, medications, and physical health issues.

Not all of the things that cause anxiety are obvious or observable in your daily life. Whatever the cause of your anxiety, know that support is available.

Even if you aren’t aware of it, there is a cause for your anxiety symptoms.

It can take time to recognize patterns or learn how to identify what activates your anxiety. It may seem like the symptoms have come out of nowhere — but that’s because your body works on autopilot when it detects a threat.

When the nervous system detects danger it activates your fight, flight, or freeze response. This causes anxiety symptoms that prepare your body for action, like:

The anxiety response is helpful in many instances, but it can become a problem when your nervous system misinterprets something harmless as a threat. In these cases, you’re reacting to something that’s not a true threat (a “false alarm”).

Over time, your body may start generalizing possible threats so that something related to a thing you’re afraid of also causes anxiety.

Can panic attacks have no cause?

A panic attack is an episode where you feel sudden and intense fear or discomfort. These attacks typically feel like they come out of nowhere, peaking within about 10 minutes before fading.

There are two types of panic attacks — expected and unexpected. An expected panic attack has a known cause, while it’s difficult to pinpoint the cause of unexpected panic attacks.

Someone’s first panic attack is likely to be unexpected because it’s a new experience. However, with time, you may learn to understand what causes them.

Once you start to see a pattern in where and when they happen, you can find ways to cope with panic attacks.

Whether or not you know what activates your anxiety, its symptoms can be very distressing.

You might have anxiety for many reasons — and some are harder to notice than others. Possible causes include:

1. Anxiety disorders

If your anxiety lasts for a long time and significantly disrupts your daily life, you may be living with an anxiety disorder.

It can take some time to work out whether there’s a pattern to your anxiety. Before you detect a pattern it can seem like your anxiety occurs at random.

The type of anxiety disorder you are diagnosed with depends on the context where your anxiety arises. Anxiety disorders include:

Keeping an anxiety journal can help you work out your triggers. You might also share your findings with a mental health professional to help them help you.

2. Genetics

The National Institutes of Mental Health (NIMH) states that “both genetic and environmental factors contribute to the risk of developing an anxiety disorder.” This means that if you have a close relative with an anxiety disorder, you’re more likely to have one.

A 2017 review reports that there is a “moderate genetic risk,” with a heritability of around 30%.

3. Trauma triggers

When someone experiences trauma, they may notice physical and mental effects long after the traumatic situation ends. Common types of trauma include abuse, neglect, and accidents.

The symptoms of post-traumatic stress can include:

  • anxiety
  • intrusive memories
  • avoiding people or places that remind you of the trauma
  • hypervigilance
  • disrupted sleep

Another symptom of trauma is being activated by trauma triggers. If you experience anxiety or panic that seems to come out of nowhere, it’s possible that it was activated by a trauma trigger you’re unaware of.

Triggers could be anything that reminds you of the trauma, whether consciously or subconsciously. Examples include:

  • sounds, like fireworks or sirens
  • certain smells
  • objects, like certain pieces of clothing
  • places or situations, like driving a car or experiencing unwanted physical touch
  • emotional states

If you think you may have symptoms of post-traumatic stress, it’s important to talk with a mental health professional for support.

4. Certain foods

For some people, certain foods can spark or worsen anxiety. Examples include:

  • sugar
  • caffeine
  • alcohol
  • processed foods

On the other hand, various foods may help with your mental health. A nutritious diet that includes protein, whole grains, fruits, and vegetables can help your body and mind feel their best.

5. Physical health problems

According to the NIMH, some physical health problems can cause anxiety symptoms or make them worse. These include heart rhythm irregularities (arrhythmia) and thyroid problems.

Certain medications or substances can also create anxiety symptoms. If you think your medication is causing anxiety, consider looking up the common side effects and talking with a doctor about your options.

If you’re having anxiety but you don’t know why, here are some things you can do to manage it.

Talking with a therapist

Various types of talk therapy (psychotherapy), such as cognitive behavioral therapy (CBT) and exposure response prevention (ERP), are evidence-based interventions to desensitize yourself to triggers.

Therapy can help you work out possible causes of your anxiety. Once you know your triggers, you can work with a therapist to overcome them and better tolerate any anxiety that arises.

Looking for a therapist, but not sure where to start? Psych Central’s How to Find Mental Health Support resource can help.

Guided breathing exercises

You can reduce your anxiety and stress levels naturally by activating your body’s relaxation response. One way to achieve this is through guided breathing exercises.

Breathing deeply for a few minutes is a fast and effective way to calm your nerves.


You can train your mind to be less reactive to your thoughts and feelings through mindfulness meditation.

For example, if you are running late for work, your reflex may be to worry, “I’m going to lose my job if I’m late!” Meditation teaches you to step outside yourself and identify that this is just a thought — not reality.

In fact, you’ve experienced this thought before and you know there’s no truth to it. By recognizing the thought, you can let it go and move forward.

Follow healthy lifestyle habits

Following a healthy, balanced diet and building regular exercise into your routine can improve your mental health.

It can help to eat whole foods, including lots of fruits and vegetables, and get the recommended amounts of protein, carbohydrates, and fat. It may also be a good idea to avoid or limit your intake of caffeine and alcohol.

When you experience anxiety, the cause isn’t always obvious. There are different types of anxiety disorders and possible reasons why you may be having anxiety symptoms.

You can do many things to manage and reduce your anxiety, including learning its cause even when you feel like there isn’t one. It may take time, but you can learn to prevent and reduce your anxiety symptoms.