Medically reviewed by
Dacelin St Martin, MD
Triple board-certified in Sleep Medicine,
Internal Medicine, and Pediatrics.
While a certain amount of anxiety in everyday life is normal, chronic anxiety is not.
A critical aspect of chronic anxiety you should be aware of is its effect on the quality of your sleep.
Chronic anxiety may be why you can’t fall asleep at night. Different research studies have shown that anxiety disorders and stress-induced anxiety can lead to behavioral and physiological changes affecting your sleeping patterns.
It’s suggested that anxiety can cause changes in the levels of certain hormones and neurons, heart rate and blood pressure, the function of immune cells, and induce behavioral changes.
The Link Between Anxiety and Insomnia
Anxiety can warn your body of potentially threatening or dangerous situations. It’s normal to experience some anxiety as a part of everyday life. However, people with an anxiety disorder experience feelings of worry or fear that may be exaggerated, frequent, or continuous.
Prolonged feelings of anxiety and stress can lead to sleeping difficulties, generally known as insomnia. Common types of insomnia include:
· Onset Insomnia: Trouble falling asleep
· Maintenance Insomnia: Difficulty remaining asleep
· Early Morning Awakening Insomnia: Waking up too early
Sleep disturbances, especially insomnia, are prevalent in people with anxiety disorders. Moreover, 24 to 36 percent of people suffering from different forms of insomnia also experience an anxiety disorder.
Sleep disturbance is considered a diagnostic symptom of generalized anxiety disorder. More than 70 percent of adults with generalized anxiety also cannot sleep well.
One population-based study revealed that 21.7 percent of the individuals with insomnia also had anxiety alone, independent of other psychiatric disorders.
These findings suggest a causal two-way relationship between anxiety and sleeplessness. Although the exact mechanism of how anxiety can lead to insomnia is not yet well determined, scientists have a few theories.
Scientists suggest that the feeling of wakefulness is an evolutionary essential for survival in stressful circumstances since it helps keep the person alert and attentive during critical situations.
Therefore, anxiety-induced stress can lead to both physiologic and behavioral changes that can cause feelings of restlessness during sleep.
Anxiety-Induced Physiological Changes
Feeling anxious can affect different components of your body’s stress system – the system that mediates your body’s response to stress. This physiological response can lead to several changes that disturb your sleeping patterns.
1) Hormonal and Neuronal Changes
Many studies showed that acute and chronic stress, common in people with anxiety, profoundly affects sleep.
Different stressors can disturb sleep by activating the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system.
Your hypothalamic system is essential to your sleep and arousal from sleep. When the hypothalamic-pituitary-adrenal (HPA) axis is activated, you feel awake and alert.
On the other hand, a corticotropin-releasing hormone (CRH) plays a crucial role in your body’s stress responses and has a stimulating effect on the HPA axis. 
When you’re in a fearful or stressful situation, as it often feels if you have anxiety, neurons containing the CRH hormone are discharged. This hormone then activates the HPA axis and the sympathetic system, which leads to wakefulness.
Furthermore, neurons that contain norepinephrine (NE) can inhibit the parasympathetic system, which controls your rest and digest states, such as sleep.
Your body’s physiological response to anxiety increases the release of NE neurons. As a result, your parasympathetic system becomes repressed, waking you up from sleep.
Therefore, anxiety can increase corticotropin-releasing hormone and norepinephrine levels, making it more difficult for you to fall asleep or stay asleep through the night.
2) Changes in Heart Rate and Blood Pressure
Feelings of anxiety and distress can cause your blood pressure to rise and your heart rate to increase.
Meanwhile, studies have shown that short sleep has been associated with an increased heart rate and high blood pressure.
Consequently, the feeling of restlessness while in bed may be because your anxiety increases your heart rate and blood pressure.
3) Changes in the Immune System
The immune system is also being investigated for its role in the relationship between anxiety and sleep.
Your immune system produces essential signaling molecules called cytokines, such as interleukin-1 beta (IL-1β), tumor necrosis factor (TNF), and interferon. Research has shown that many cytokines also play a significant role in regulating sleep.
The levels of cytokines are altered in people with certain anxiety disorders, such as generalized anxiety disorder, which is usually abnormal.
Anxiety-Induced Behavioral Changes
We know that unpleasant or stressful thoughts can keep you up at night. You go into bed, everything is calm and quiet, and you’re left to your thoughts. Your anxiety kicks in, you can’t stop thinking, and you can’t fall asleep.
Everyone goes through that at least a few times during their lives.
Nonetheless, when that happens often enough, commonly in individuals with anxiety disorders, your body may develop a misguided coping strategy by becoming used to staying awake once you get into bed.
If this happens regularly, your mind starts associating going to bed, your bedroom, and other sleeping conditions with staying awake. This effect is known as conditioned arousal or conditioned insomnia.
Additionally, people with anxiety who experience sleep disturbances may start worrying about not getting enough sleep. These types of worries can lead to behaviors that contribute to their insomnia, such as staying longer in bed to catch up on sleep and constantly checking the clock at night.
This worry over getting enough sleep can develop into sleep-related anxiety that further increases trouble with sleeping and leads to a vicious cycle of anxiety and insomnia.
If you’re continuously having difficulty falling asleep or staying asleep, consult with a healthcare professional.
If you’re also suffering from anxiety, it may be causing your insomnia. There are different types of treatment options for various anxiety disorders that can help you overcome your phobia and sleep better at night.
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