Many people sleep with a bedside lamp, television, or other light source on, maybe just for convenience. But sleeping in a bright room that is often lit can interfere with the body’s natural sleep-wake cycle and hormone regulation,” said gynaecologist Dr Mitali Rathod. Even if light is not a risk factor at night, frequently sleeping with lights on can cause sleep quality to be low and the hormones that are responsible for the body’s internal clock to be low.
There is research that light exposure during the usual sleeping hours can suppress melatonin production, a hormone that signals to the body to sleep. A good sleep is critical for health in general - for physical recovery, mental health, and hormonal balance.
Light affects the internal clock in the body
The body has a circadian rhythm and is a 24-hour internal clock that functions around the body to monitor sleep, wakefulness, hormone release, digestion, and body temperature.
Related Articles
Light from natural daylight helps to align this rhythm with the day-night cycle. In the evening, as light levels decrease, melatonin production is increased in the brain and this is associated with relaxation and sleepiness.
Artificial light particularly bright or blue-enriched light from electronic devices and some LED bulbs can delay this process by signaling to the brain that it is still daytime.
The Role of Melatonin
Melatonin is produced by the pineal gland in response to darkness. It is used to regulate the timing of sleep.
Related Articles
Healthy melatonin production may contribute to:
- Easier sleep onset
- Better sleep quality
- Maintenance of the body's circadian rhythm
Melatonin is important for sleep, but hormone regulation is complex and involves many factors, including age, stress, medical conditions, medications, and lifestyle.
How sleeping with lights on may affect hormone production and how it impacts hormones
Dr Rathod points out that disruption of normal sleep patterns can also have broader effects on hormonal health.
The negative effects of poor sleep or chronic exposure to nighttime light on one’s sleep are:
Reduced Melatonin Production
Exposure to light during sleep can suppress melatonin secretion, making it harder for some individuals to fall asleep or stay asleep.
Disrupted Circadian Rhythm
If the body’s internal clock is not on time, a shift in sleep schedule and frequent nighttime light exposure could cause hormone release to be affected.
Effects on Stress Hormones
Cortisol, a stress hormone, can be affected by poor sleep quality. Cortisol is naturally circadian and peaks in the morning and decreases in the evening. In some cases, chronic sleep disruption can interfere with this pattern.
Metabolic Hormones
Sleep deprivation has been associated with changes in hormones that drive appetite regulation (such as ghrelin and leptin) that may affect hunger and satiety. Such changes are associated with insufficient sleep, not light exposure.
Why sleep is crucial for women's health
Sleep supports many aspects of women’s health throughout different stages of life.
Adequate sleep may help support:
- Menstrual health
- Emotional well-being
- Cognitive function
- Immune function
- Energy levels
- Recovery
Hormonal fluctuations during menstruation, pregnancy, postpartum period, and menopause also affect sleep quality. Women who are having chronic sleep problems should talk to a healthcare professional about it.
Other Effects of sleeping with lights on
Besides hormone regulation, sleeping in a bright environment may contribute to:
- Difficulty falling asleep
- More frequent nighttime awakenings
- Feeling less refreshed upon waking
- Reduced sleep duration
Individual responses vary, and some people can be more sensitive to nighttime light than others.
Tips for a Better Sleep Environment
For the benefit of sleep quality, designing a sleep-friendly bedroom should be done.
Keep the Room Dark
Turn off unnecessary lights before bedtime. If complete darkness is not possible, consider blackout curtains or a comfortable sleep mask.
Limit Screen Time Before Bed
Smartphones, tablets, computers, and televisions emit light that can delay sleep for some people. Screen use should be decreased by 30–60 minutes before bedtime.
Maintain a Consistent Sleep Schedule
Going to bed and waking up at the same time every day supports a healthy circadian rhythm.
Create a Relaxing Bedtime Routine
Reading a book, practicing gentle stretching, meditating, or listening to calming music may help prepare the body for sleep.
Keep the Bedroom Comfortable
A good sleep environment is cool, quiet, and comfortable, which promotes better rest.
When to Seek Medical Advice
Occasional poor sleep is common, but persistent sleep difficulties should not be ignored.
Speak with a healthcare professional if you experience:
- Difficulty sleeping for several weeks
- Excessive daytime sleepiness
- Loud snoring or pauses in breathing during sleep
- Persistent fatigue despite adequate time in bed
- Symptoms of anxiety or depression affecting sleep
A healthcare provider can evaluate possible underlying causes and recommend appropriate treatment.
The Bottom Line
Sleeping with lights on may interfere with the body's natural production of melatonin and disrupt the circadian rhythm, potentially affecting sleep quality.
Dr Mitali Rathod's advice underscores the importance of protecting your sleep environment as part of a healthy lifestyle. Although sleeping with lights on is unlikely to cause immediate hormonal problems, regular nighttime light exposure may contribute to disrupted sleep patterns and reduced melatonin production in some people.
Comments 0