How Does Sleep Affect Your Heart Rate?

Have you ever noticed your heart racing after a poor night’s sleep? Or maybe your smart watch has shown a higher resting heart rate after tossing and turning? Sleep plays a vital role in regulating your heart rate and protecting your overall cardiovascular health, yet many people unknowingly suffer from insomnia, which can throw this delicate balance off track.

In this article, we’ll explore how your heart rate changes during sleep, why insomnia matters more than you might think, and what you can do to support both better sleep and a healthier heart.

‍

What Happens to Your Heart Rate When You Sleep?

During a healthy night's sleep, your heart rate naturally slows as you progress through different sleep stages. Here’s what typically happens:

• Non-REM Sleep (especially deep sleep): Your heart rate and blood pressure drop as your body enters a restful state. This allows your heart to take a much-needed break.
• REM Sleep (dream stage): Your heart rate may become more variable, sometimes speeding up slightly, similar to when you're awake.

This nightly pattern is important - it gives your cardiovascular system time to reset and recover from the day.

‍

Insomnia and Heart Rate: What’s the Connection?

Insomnia isn’t just about struggling to fall asleep. According to the NHS, it also includes waking frequently during the night, rising too early, or feeling unrefreshed after sleep; issues that many people don’t realise could meet the criteria for clinical insomnia.
‍

When you don’t get enough quality sleep:

• Your body doesn’t cycle through sleep stages properly.
• Your heart rate may stay elevated during the night, rather than slowing as it should.
• You may experience more stress hormone activity, like cortisol, which keeps your heart and body in a state of alertness.

‍

How a Resting Heart Rate Reflects Sleep Quality

Your resting heart rate (RHR) is a good indicator of your sleep health:

• A low RHR (typically 60–100 bpm for adults) during sleep suggests your body is resting well.
• A consistently elevated RHR may point to stress, poor sleep, or other underlying health issues.

Many wearable fitness devices now track heart rate variability (HRV), which offers even more insight into your sleep stages and stress levels.

‍

Could You Have Insomnia Without Realising?

It’s estimated that 1 in 3 people in the UK experience insomnia symptoms at some point. However, many don’t realise that their constant fatigue, poor concentration, or increased heart rate at rest could be linked to sleep disturbances.

Insomnia is often underdiagnosed because people normalise poor sleep, especially if it has become part of their routine.

‍

Tips to Improve Sleep and Heart Health

Improving your sleep can help normalise your heart rate and support overall wellbeing. Here are some practical strategies:

1. Establish a consistent bedtime and wake-up time.
2. Limit caffeine and alcohol, especially in the evening.
3. Turn off screens at least an hour before bed to avoid blue light disruption.
4. Try relaxation techniques like deep breathing, meditation, or a warm bath.
5. Seek support: Cognitive Behavioural Therapy for Insomnia (CBT-I) is a proven, drug-free way to retrain your brain for better sleep. It’s also the first-line treatment recommended by the NHS for chronic insomnia. Sleepio is a CBT-I treatment that works with you to develop a personalised insomnia treatment plan, empowering you to challenge negative thought patterns, establish healthy sleep habits, and enjoy restful nights of sleep.

‍

In summary, your heart rate naturally slows during sleep; but if you’re struggling with insomnia, this process can be disrupted, increasing your risk of heart-related problems. Many people live with insomnia without realising it, blaming stress, lifestyle, or ageing for their fatigue. If you’re regularly tired, anxious, or have a high resting heart rate, it might be time to look at your sleep habits more closely.

‍