Expert Answers to Common Questions About Improving Sleep Quality

This detailed guide provides scientifically backed answers to key questions about getting the most out of each stage of sleep so you can wake up feeling energised.

Published: Wednesday 31 July 2024


woman holding a cup and sitting on a bed

The quality of sleep an individual receives each day can affect numerous key physical and cognitive functions, from viral immunity and musculoskeletal growth to memory consolidation and emotional regulation.

Therefore, it is important to understand how to improve sleep quality, whether through lifestyle adjustments or by using clinically proven sleep treatments after consulting a medical professional.

This guide offers detailed, scientifically backed advice on how to get better sleep by providing answers to some of the most common questions about improving sleep quality during the various stages of sleep.

How is sleep quality measured?

Sleep quality can be measured by tracking an individual's physical movements and fluctuations in their heart rate, brain waves, breathing, and skin temperature while sleeping.

This data may be subsequently cross-checked against subjective measures of sleep quality, such as how an individual feels upon waking up, to accurately gauge sleep quality.

According to the current scientific literature, the metrics outlined above are core aspects of three key methods of measuring sleep quality[1][2][3]:

  • Polysomnography - This method involves connecting sensors to the body to monitor brain waves, heart rate, breathing, and other physiological functions while sleeping to measure sleep quality throughout the various stages of sleep.
  • Actigraphy - This method requires individuals to wear a device on their wrists, such as a smartwatch with sleep-tracking capabilities, to record movements and determine how deeply an individual is sleeping. Deep sleep can induce certain movements, such as shudders and pulses of muscular function, which can be picked up through actigraphy and which differ from conscious movements such as waking temporarily to switch sides.
  • The Pittsburgh Sleep Quality Index - This is an older and less accurate method of measuring sleep quality than polysomnography and actigraphy. It requires individuals to answer questions about their daily sleep over an extended period, such as a month, to provide a qualitative assessment of how well an individual sleeps.

Recommended reading: What happens to your body when you are sleeping?

Which factors affect sleep quality?

Sleep hygiene

Sleep hygiene refers to the consideration of various environmental factors that collectively affect sleep quality[4]. Some of the key aspects of sleep hygiene include:

  • Reducing natural light exposure while sleeping by keeping phones face down, lamps switched off, and using curtains to block natural light that may stream in the morning.
  • Maintaining a steady, cool room temperature between 16 and 18 degrees Celsius through the use of fans, heaters, or air conditioners.
  • Making the bed before sleeping in it, and keeping duvets or blankets nearby, to maximise comfort.

Accounting for these factors can help increase sleep quality by raising the body’s levels of a hormone called melatonin, which regulates the sleep-wake cycle and promotes restful sleep[5].

Meal timings

Eating meals too close to bedtime may result in digestive discomfort, disrupting sleep quality. Moreover, late meals can cause spikes in blood sugar levels, delaying the onset of sleep.

As such, it is important to finish eating at least two to three hours before bedtime to allow ample time for digestion to occur and for the body to relax and ready itself for sleep.

Recommended reading: How Sleep Can Help Weight Loss

Anxiety and stress

Elevated levels of a hormone called cortisol in the blood can keep the body in a heightened state of alertness, delaying sleep onset and reducing sleep quality[6].

Implementing relaxation techniques such as meditation or deep breathing before going to bed can help reduce feelings of anxiety and stress, normalise blood cortisol levels, and improve sleep quality as a result.

Caffeine consumption

According to studies[7], caffeine blocks a neurotransmitter called adenosine from slowing down nerve activity, leaving the individual feeling awake and alert.

Caffeine has an average half-life of approximately five hours, which means it takes five hours for the concentration of caffeine in the blood to halve after it is consumed through caffeinated beverages such as coffee.

This time frame implies that consuming a high amount of caffeine or taking caffeine late in the day can delay sleep onset and shorten deep sleep stages.

Alcohol consumption

Alcohol is a sedative, which may cause some individuals to think it can help improve sleep quality. However, this is a misconception - alcohol often results in non-restorative sleep by shortening the duration of the deeper stages of sleep that are crucial for memory and mood regulation[8].

It is therefore advisable to limit alcohol consumption and avoid it at least three hours before sleeping to help improve sleep quality.

Physical activity

Engaging in regular physical activity decreases the body's cortisol levels, making it easier to relax and fall asleep. Moreover, the body's core temperature rises during physical activity before dropping post-exercise. This drop is associated with enhanced sleep onset and maintenance, exemplifying the importance of engaging in light to moderate exercise each day, if possible.

Medication usage

Certain classes of medication contain active ingredients that can reduce sleep quality in various ways. This includes:

  • Alpha-blockers for the treatment of blood pressure issues - studies show that alpha-blockers may interfere with the regulation of neurotransmitters involved in the sleep-wake cycle, reducing the amount of REM sleep an individual experiences[9].
  • Antidepressants and SSRIs can alter the balance of a neurotransmitter called serotonin, which may reduce the quality of restorative deep sleep.
  • Stimulants prescribed to treat ADHD symptoms - stimulants are formulated to increase brain activity and alertness, making it harder to relax and fall asleep.
  • Medication containing caffeine - medicines containing caffeine, such as Lemsip Max Capsules, can increase nerve activity, keeping the brain alert and impairing sleep.

Recommended reading: What happens if we don’t sleep well?

What is the best way to improve sleep quality during each stage of sleep?

The transition stage

The transition stage is the initial stage of sleep and refers to the transition between wakefulness and sleep. Therefore, it is not possible to experience high-quality sleep during the transition stage, although individuals can decrease the time taken to enter subsequent deeper stages of sleep through methods such as:

  • Improving sleep hygiene
  • Engage in relaxing activities such as reading a book
  • Avoiding stimulating activities such as using a phone before going to bed
  • Limiting caffeine and heavy meals in the evening

The early NREM stage

The early NREM (Non-Rapid Eye Movement) stage of sleep refers to the moment when an individual is no longer awake and has just begun to sleep. Sleep quality during this stage can be improved by:

  • Ensuring the bedroom is at a comfortable temperature
  • Keeping phones on silent
  • Turning off lamps and eliminating other similar sources of sensory distraction
  • Moderating one’s fluid intake before bed to reduce the probability of needing to wake up in the middle of deep sleep to use the toilet

The slow wave stage

The slow wave stage occurs before the deepest (REM) stage of sleep. During this stage, sleep quality can be improved by:

  • Maintaining a consistent sleep schedule to regulate the circadian rhythm, which is closely linked to improving sleep quality during the slow wave stage
  • Ensuring the bedroom is dark, quiet, and cool

The REM stage

The REM (Rapid Eye Movement) stage refers to a unique phase of sleep during which cognitive functions such as learning and emotional regulation are restored. REM sleep quality can be improved by:

  • Engaging in meditation and deep breathing exercises to alleviate stress and anxiety before sleeping, thereby reducing the likelihood of experiencing nightmares that may interrupt REM sleep
  • Limiting caffeine and alcohol intake before sleeping, due to their effects on sleep quality

Recommended reading: A Guide to Sleeping Better at Night

Which sleep treatments can improve sleep quality?

Nytol

Nytol is a sleep aid containing 25 mg of the active ingredient diphenhydramine hydrochloride. Diphenhydramine blocks receptors in the brain that regulate wakefulness, making individuals feel more drowsy and facilitating the transition into sleep.

Nytol takes 20 to 30 minutes to take effect, with the effects lasting four to six hours. This can increase the total time slept, making it more likely for individuals taking Nytol to reach the deeper stages of sleep.

Nytol One-A-Night

Nytol One-A-Night contains 50 mg of the active ingredient diphenhydramine hydrochloride. It works in the same way as Nytol, by blocking histamine receptors in the brain involved in regulating wakefulness.

Nytol One-A-Night can help improve sleep quality by reducing the time taken to enter the transitionary stage of sleep, similar to Nytol. Individuals can expect to feel the onset of effects within 20 to 30 minutes of taking Nytol One-A-Night, and its effects can last for up to six hours, supporting longer periods of sleep and helping individuals progress into deeper sleep stages.

Nytol Herbal

Nytol Herbal contains natural herbal ingredients such as hops, Valerian root, and passion flower. Hops contain a flavonoid called xanthohumol, which is thought to interact with the GABA (gamma-aminobutyric acid) system in the brain that regulates relaxation and the excitability of neurons. In doing so, hops can contribute to feeling relaxed and less anxious, making it easier to fall asleep and reducing the probability of the deeper stages of sleep being impacted.

Passionflower and Valerian root have also been shown to increase levels of gamma-aminobutyric acid (GABA) in the body, which can induce feelings of calmness and reduce the time it takes to fall asleep.

Nytol Herbal One-A-Night

Nytol Herbal One-A-Night contains 385 mg of Valerian root extract, in addition to hops and passionflower. These herbal ingredients can help improve sleep quality through the same scientific mechanisms as Nytol Herbal, with the primary difference being the higher concentration of Valerian root extract.

Recommended reading: How to Get to Sleep Fast

What are some common misconceptions about improving sleep quality?

Alcohol improves sleep quality

There is no scientific evidence to suggest alcohol improves sleep quality. While it is true that alcohol increases the production of neurotransmitters that initially induce drowsiness, the body metabolises the alcohol even while sleeping, causing its sedative effects to wane. This can contribute to fragmented sleep, leading to frequent awakenings during the night.

The reduction in REM sleep, which is crucial for cognitive functions and emotional regulation, results in poorer overall sleep quality and diminished restorative benefits.

Cannabis improves sleep quality

Cannabis can cause muscular relaxation, inducing drowsiness and sleep. However, the prolonged use of cannabis, especially if the strains contain a high concentration of THC, reduces how much REM sleep an individual experiences while sleeping.

The reduction in REM sleep can impair cognitive functions and emotional regulation, resulting in a 'brain fog' upon waking up due to a lack of good-quality sleep. Chronic cannabis use can also result in dependency, making it harder to sleep without using the substance.

Sex improves sleep quality

According to research, sex may improve sleep quality, particularly if it results in an orgasm which triggers the release of oxytocin and endorphins that promote relaxation and reduce stress.

Oxytocin induces feelings of calmness and emotional bonding, while endorphins enhance mood and act as natural painkillers. This combination can lead to a decrease in anxiety and an overall sense of well-being, making it easier to fall asleep and potentially improve the quality of sleep.

However, studies show that improvements in sleep quality from having sex before bed may result from the stronger emotional bond one may feel with their partner following intercourse. This implies that although sex before bed can promote relaxation, it does not guarantee improved sleep quality for everyone.

Summary

Improving sleep quality requires a step-by-step approach to getting the most from each stage of sleep. It can also be useful to measure sleep quality through methods such as actigraphy or simply wearing a smartwatch or device, although this may not be practical for some individuals.

As such, it is advisable to focus on addressing the factors that can affect sleep quality, including but not limited to one’s sleep hygiene, meal times, and the amount of caffeine and alcohol consumed each day. Taking sleep treatments after consulting a pharmacist in addition to addressing these factors can maximise sleep quality as much as possible.

At Pharmica, we offer a wide range of clinically proven sleep treatments formulated to help enhance sleep quality. We are rated 4.9/5 from more than 196,000 reviews and have played a part in the health journeys of more than 1.35 million customers.

Browse our range of treatments today.

  1. Harrison et al. (2021). Sleep time and efficiency in patients undergoing laboratory-based polysomnography. Journal of Clinical Sleep Medicine, 17(8), pp. 1591-1598. doi: https://doi.org/10.5664%2Fjcsm.9252. [Accessed: 31 July 2024].
  2. Forner-Cordero et al. (2018). Comparison of sleep quality assessed by actigraphy and questionnaires to healthy subjects. Sleep Science, 11(3), pp. 141-145. doi: 10.5935/1984-0063.20180027. [Accessed: 31 July 2024].
  3. Mollayeva et al. (2016). The Pittsburgh sleep quality index as a screening tool for sleep dysfunction in clinical and non-clinical samples: A systematic review and meta-analysis. Sleep Medicine Reviews, 25, pp. 52-73. doi: 10.1016/j.smrv.2015.01.009. [Accessed: 31 July 2024].
  4. NHS (n.d.). How to fall asleep faster and sleep better. Available at: https://www.nhs.uk/every-mind-matters/mental-wellbeing-tips/how-to-fall-asleep-faster-and-sleep-better/. [Accessed: 31 July 2024].
  5. Zisapel (2018). New perspectives on the role of melatonin in human sleep, circadian rhythms and their regulation. British Journal of Pharmacology, 175(16), pp. 3190-3199. doi: 10.1111/bph.14116. [Accessed: 31 July 2024].
  6. Healthline (n.d.). How does Cortisol affect your sleep? Available at: https://www.healthline.com/health/cortisol-and-sleep. [Accessed: 31 July 2024].
  7. Reichert et al. (2022). Adenosine, caffeine, and sleep–wake regulation: state of the science and perspectives. Journal of Sleep Research, 31(4), e13597. doi: 10.1111/jsr.13597. [Accessed: 31 July 2024].
  8. Nierenberg (2022). Why Does Alcohol Mess With My Sleep? Available at: https://www.nytimes.com/2022/01/25/well/mind/alcohol-drinking-sleep.html. [Accessed: 31 July 2024].
  9. Radulovacki et al. (1980). Elimination of REM sleep rebound in rats by alpha-adrenoreceptor blockers, phentolamine and phenoxybenzamine. Pharmacology, biochemistry, and behaviour, 13(1), pp. 51. doi: 10.1016/0091-3057(80)90120-3. [Accessed: 31 July 2024].
Rehma Gill

Written by: Rehma Gill

Pharmacy Manager・GPHC Number 2225869

Rehma completed her pharmacy degree at the University of Portsmouth in 2019 and went on to complete her internship in community pharmacy. As a pharmacy manager and a responsible pharmacist here at Pharmica, Rehma’s responsibilities include managing day-to-day operations at the pharmacy and ensuring we provide outstanding service to our patients.


Carolina Goncalves

Medically Reviewed by: Carolina Goncalves

Superintendent Pharmacist・GPHC Number 2088658

Carolina Goncalves is the Superintendent Pharmacist at Pharmica, where she ensures patients receive exceptional healthcare and support, as part of a seamless online pharmacy service.

With a comprehensive professional background spanning more than 13 years, Carolina has extensive experience supporting Men’s and Women’s health. Carolina is responsible for providing expert treatment advice to thousands of patients in areas such as Sexual Health, Erectile Dysfunction, Hair Loss, Weight Loss and Asthma.


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