From Memory Loss to Heart Disease, Stress and Insomnia Can Take a Toll

How does stress specifically affect the body and thus sleep?

It really has a physiological effect across our whole body. Our heart rate might be faster. Our blood pressure might increase. We may start to breathe more quickly and even feel short of breath. Our muscles tend to contract and tighten. Stress can also result in muscle pain or headaches. Some people get GI upset. And those physical symptoms can also impact our sleep negatively.

What’s the hypothalamic-pituitary-adrenal (HPA) axis, and how does it factor into stress and poor sleep?

It’s a part of our body’s stress management system. In response to stress, the HPA axis releases cortisol. That’s a totally normal stress response and is very healthy, but when we’re experiencing chronic stress, then that HPA axis is in overdrive. And it’s releasing these really prolonged, high levels of cortisol, and unfortunately that can increase our health risks and affect our sleep.

Should people with sleep troubles have their cortisol levels tested?

Our cortisol levels change throughout the day, and so it’s not really feasible to do a blood test to test those levels (unless a doctor suspects a cortisol-related underlying disease). And I think that we can be a good judge of when we’re feeling that impact of chronic stress and then acknowledging that it may be time to address it by speaking with your health provider or a psychologist or counselor for stress-management strategies. Addressing it is probably more important than getting that specific number.

How can serious sleep issues affect physical health?

Chronically insufficient sleep or untreated sleep disorders can increase risks for a number of health problems, including excessive weight gain, cardiovascular disease and diabetes. Beyond those kinds of longer-term consequences, poor sleep can also negatively impact our immune system, so it makes it harder to fight off illness. And then definitely poor sleep can impact our emotion regulation and increase our risk for anxiety and depression symptoms.

So mental health can cause sleep problems, and sleep problems can cause mental health issues?

Yeah, it’s definitely this bi-directional relationship. But, on the flip side, if we treat sleep problems, sometimes that can benefit our mental health, and if we treat anxiety or depression, sometimes that has a benefit on sleep as well.

What’s the weight-gain connection?

There’s some evidence that when we are getting insufficient sleep, we may eat more. Also not getting enough sleep may impact our hormone regulation, including our appetite-regulating hormones. And when we’re awake late at night, it’s less likely that we’re going to be eating healthful foods. Unhealthful foods are common with late-night snacking. There’s also emerging evidence that the timing of when we eat is important as well, so eating late at night may have a particularly negative effect on our health.

How does poor sleep potentially affect memory?

There are functions of our brain when we sleep that really help to consolidate our memories (short bursts of brain wave activities called sleep spindles are a prime focus of research today and thought to play a significant role in memory consolidation and cognitive function). When working with adolescents, I’ll tell them: Don’t pull an all-nighter. Get a good night of sleep before the exam if you want to do really well. If we aren’t getting enough sleep, it impacts our attention, our concentration, which can also play into memory. And long-term, there is some emerging research suggesting that sleep problems may be a risk factor for developing memory disorders like Alzheimer’s.

Here comes the sun: Many experts agree on one effective way to help maintain circadian rhythms (your biological clock’s timing) for better sleep: Step outside and soak in some sun for a few minutes each morning. Some scientists also suggest catching a few rays in the evening, as the sun’s light fades to dusk.

What is the circadian rhythm connection?

Our circadian rhythms are our body’s internal clocks. The timekeeper of our body helps to regulate our sleep-wake cycles as well as other bodily functions across the 24-hour day. Our circadian system is regulated by the light-dark cycle and also other daily cues, such as the timing of our eating or our physical activity. If our sleep is disrupted due to stress, we may be spending more time awake at night, and that could impact circadian rhythms. Or if we’re scrolling on our phones during evening hours, that bright light from our electronic devices can delay circadian rhythms.

Is there a correlation between stress and stressful dreams?

Certainly, when we are stressed, we may be more susceptible to nightmares or stressful dreams. Stress can, physiologically, really impact our body and can result in night awakenings. We may feel like we have poorer sleep quality or that our sleep is more fragmented.

Can chronic stress lead to a chronic sleep problem?

Sometimes, we may be having a number of poor nights of sleep and try to compensate for that by allowing ourselves to sleep in later or take naps during the day. Or we might go to bed really early to try to catch up on that sleep, and sometimes that can have an unintended consequence of leading to more chronic sleep problems, such as insomnia, where you’re having a lot of difficulties falling asleep, staying asleep or having early morning awakening. So, yes, that can unfortunately lead to ongoing sleep problems.

This interview was edited for length and clarity.

Read more on how to address sleep problems.