What Is Blue Light? How Does It Impact Sleep?

Updated Dec 14, 2024 | 10:45 PM IST

SummaryScreens of electronic devices such as smartphones, computers, tablets, and televisions emit blue light. But does it impact your natural sleep cycle and circadian rhythm?
Blue Light

Blue Light (Credit: Canva)

Blue light emitted by devices like smartphones, computers, and televisions is becoming a major factor disrupting our sleep cycles. Research reveals that a significant number of Americans use electronic devices close to bedtime, contributing to poor sleep quality. Reducing exposure to blue light, particularly in the evening, is a simple yet effective way to help your body prepare for restful sleep.

What Is Blue Light?

Blue light is part of the visible light spectrum and is emitted by natural and artificial sources like the sun, fluorescent lights, LED lights, and digital screens. This wavelength is known for influencing our alertness, mood, and sleep patterns. During the day, blue light plays a role in regulating circadian rhythms, helping us stay alert and focused. However, exposure to it in the evening can have a detrimental effect on sleep quality.

How Does Blue Light Impact Circadian Rhythms?

Circadian rhythms are 24-hour cycles that control essential bodily functions, including sleep. Light is the primary factor that aligns these rhythms with day and night. Historically, exposure to sunlight during the day helped set our body clocks, signaling when to be awake and when to sleep. However, the widespread use of artificial lighting and electronic devices has introduced more light exposure after dark, disrupting these natural cycles.

Blue light, in particular, has the strongest impact on circadian rhythms. During daylight hours, blue light helps us feel alert by stimulating the brain, raising body temperature, and increasing heart rate. But in the evening, exposure to blue light can confuse the body’s internal clock, suppressing melatonin—the hormone responsible for making us feel sleepy. As a result, our brains may remain in “daytime mode,” preventing us from winding down for the night.

Health Consequences Of Disrupted Sleep

Persistent disruption of circadian rhythms can lead to a range of health issues, including metabolic disorders, poor mental health, and increased risk for conditions like depression and anxiety. Furthermore, the inability to sleep well at night affects cognitive performance, mood, and overall well-being. Chronic exposure to blue light in the evening may significantly contribute to these negative health outcomes.

Devices That Emit Blue Light

Many common devices in our daily lives emit blue light, including:

- Smartphones and tablets

- Computer monitors and laptops

- Televisions and e-readers

- LED and fluorescent lighting

- Video game consoles

How To Minimize Blue Light Exposure

To reduce the effects of blue light on your sleep, here are some practical strategies:

1. Turn off screens before bed: Try to avoid using electronic devices at least two to three hours before bedtime. Reducing screen time helps prevent blue light from interfering with melatonin production.

2. Adjust your lighting: Dim your home’s lights or switch to warmer-toned lighting in the evening. You can also use lamps with red or orange light, which are less likely to impact your circadian rhythms.

3. Night mode settings: Many smartphones and computers have a "night mode" feature that reduces blue light emission. Make use of these features to limit exposure in the hours leading up to bedtime.

4. Blue light-blocking glasses: Special glasses designed to filter out blue light may be helpful for some individuals. These glasses can block or reduce the melatonin-suppressing effects of blue light.

5. Apps for blue light reduction: There are several smartphone and computer apps available that reduce blue light emission, allowing you to use your devices before bed without disturbing your sleep.

6. Create a sleep-friendly environment: If you can’t control light sources in your bedroom, consider using an eye mask to block out ambient light and promote better sleep.

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Lung Health After 40: Natural Changes, Warning Signs And Ways To Protect Your Lungs

Updated Aug 8, 2026 | 07:00 PM IST

SummaryAfter 40, lung function naturally declines, making it important to recognise warning signs and protect lung health through exercise, avoiding pollutants, vaccinations, and regular check-ups.
Lung Health After 40: Natural Changes, Warning Signs And Ways To Protect Your Lungs

Credit: AI

By the time we enter our 40s, the lungs begin to undergo gradual changes that can affect breathing capacity and respiratory reserve. While some changes are a normal part of ageing, persistent cough, breathlessness or recurrent chest infections should not simply be dismissed as getting older.

Experts explain why lung health deserves greater attention after 40, which everyday habits can help protect the lungs, and when screening or medical evaluation may be needed.

As we enter our 40s, what natural changes occur in our lungs, and why does lung health become more important at this stage of life?

As we age lung tissue elasticity declines and chest wall mechanics stiffen. From an oncology standpoint, age-related cellular damage and long-term exposure to cancer causing agents like tobacco increase cancer risk. Looking after lung health from young age builds the respiratory reserve needed to tolerate advanced medical or surgical interventions if required as you get older.

What everyday lifestyle habits can help keep our lungs healthy after 40?

Engage in regular aerobic conditioning exercises to maintain full breathing capacity. Reduce carcinogen exposure by avoiding active and passive tobacco smoke, and ensuring proper ventilation while cooking. using HEPA air purifiers may help to an extent. Maintain an antioxidant-rich diet to combat cellular oxidative stress.

Also read: Dream Of Becoming A Footballer Or Cricketer? Cardiologists Reveal Heart-Healthy Habits For Young Athletes

What are some early signs of declining lung health that people often dismiss as 'just ageing' but should actually get checked?

2 to 3 week cut off is applicable here. A persistent cough lasting over three weeks, progressive exertional breathlessness, recurrent chest infections, coughing up blood, or unexplained weight loss are red flags. This is for both smokers and nonsmokers. Early-stage lung cancers are frequently asymptomatic or subtle; ignoring these signs delays diagnosis. These symptoms are that of TB as well. So, that should be ruled out.

Are there any health screenings, vaccinations, or routine check-ups that adults over 40 should consider to protect their lung health?

Annual flu and once in lifetime pneumococcal vaccine prevents severe pulmonary infections. For high-risk individuals—such as heavy past or present smokers—a annual Low-Dose CT (LDCT) scan is the gold standard for early lung cancer detection, finding lesions when they are most curable. Eliminating tobacco, mitigating indoor air pollution, exercising, and maintaining balanced nutrition significantly lower cancer risk and improve overall survival outcomes.

By Dr. Sandeep Nayak, Chairman of Oncology, MACS-Renova Oncology Institute, KIMS Hospital, Bangaluru

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Decoding The Fertility Markers

Updated Aug 8, 2026 | 05:00 PM IST

SummaryFertility markers such as menstrual patterns, ovulation signs, ovarian reserve tests, and hormone levels can offer insights into reproductive health, but they cannot predict fertility with certainty.
Decoding The Fertility Markers

Credit: AI

A blood test is considered the first step towards fertility enquiries, but for many, the results might seem like a confusing jumble of numbers and acronyms. Reports sometimes contain terms like AMH, FSH, LH, AFC, and estradiol, which makes patients confused if a single "abnormal" figure indicates they are unable to conceive.

The truth is more reassuring, and more nuanced. Fertility experts stress that a person's fertility cannot be ascertained by a single test. Instead, these markers serve as parts of a bigger picture, assisting fertility specialists in comprehending reproductive health and suggesting the best course of action when necessary.

Fertility Tests Are Guides, Not Verdicts

The idea that a single blood test can determine whether a woman would naturally become pregnant is one of the most widespread myths. Age, egg quality, ovulation, sperm health, uterine health, lifestyle, and underlying medical issues are some of the factors that actually affect fertility.

Although diagnostic markers offer useful information, they must always be interpreted in conjunction with the couple's overall reproductive profile, clinical history, and ultrasound results.

Also read: How Menopause Changes Heart Health Risks?

Understanding The Ovarian Reserve “AMH”

Many women with low AMH can still achieve successful pregnancies, especially if they continue to ovulate regularly. Similarly, women with high AMH are not necessarily more fertile, elevated AMH levels in women also means Polycystic Ovary Syndrome (PCOS), where ovulation may actually be irregular. For fertility specialists, AMH is useful in predicting the number of eggs that are likely to respond to ovarian stimulation medication, based on which they customize IVF treatment.

Also read: Making IVF Affordable: Experts Push For Insurance Cover, Public Funding & Better Access To Fertility Care In India

FSH Determines Ovarian Function

Our pituitary gland produces Follicle Stimulating Hormone (FSH) and this hormone helps in stimulating egg development.

Usually, the second or third day of the menstrual cycle is when FSH is measured. If ovarian reserve is reduced, that is higher-than-normal levels, which may imply that ovaries need more stimulation to mature eggs. From cycle to cycle the FSH levels change.

Also read: NCR's Long Commutes Are Stealing Sleep & Affecting Reproductive Health

LH And The Ovulation Story

FSH and luteinizing hormone (LH) cooperate to control ovulation. The ovary releases a developed egg in response to an increase in LH.

LH levels may be disproportionately greater than FSH in PCOS-affected individuals, which can lead to irregular menstrual periods and ovulation. Instead of using LH alone, fertility specialists assess it in link with other hormone markers.

Also read: World Embryologist Day: What Really Happens Inside An IVF Lab?

Estradiol And AFC: Completing The Picture

An indicator of ovarian activity during the menstrual cycle is estradiol (E2), a type of estrogen generated by growing follicles. Combined interpretation is crucial since elevated early-cycle estradiol levels can occasionally conceal an elevated FSH.

The Antral Follicle Count (AFC), which is done via a transvaginal ultrasound, is another crucial evaluation. AFC gives an additional indication of ovarian reserve by counting the number of visible tiny follicles in the ovaries.

Indeed, the combination of AMH and AFC provides a more thorough insight than any test by itself.

Also read: World IVF Day: Why Men Need To Be Part Of The Fertility Conversation

Fertility Evaluation Isn't Just For Women

Female hormone testing frequently receives greater attention, whereas male fertility contributes to roughly half of all infertility issues.

A semen screening remains one of the most significant and cost-effective tests, measuring sperm count, mobility, and morphology. When necessary, additional hormonal or genetic tests might be suggested.

Era Of Self-Diagnose

After getting a test report, many people search the web for quick answers, but those disguised numbers without proper medical context from a specialist can erupt unnecessary tension.

The fertility markers depend on a variety of factors, some of which include: age, weight, menstrual history, prior pregnancies, medications, hormonal status, and lifestyle.

Therefore, understanding the parameters like “low” or “high” online may create chaos within the individuals. Instead, consult a fertility specialist to decode the report.

By Dr Rubeena Zainab, Senior Consultant - Reproductive Medicine, Milann Fertility and Birthing Hospital, Bengaluru

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Are Girls Today More Aware Of Period Hygiene? Why Education Still Matters

Updated Aug 8, 2026 | 03:00 PM IST

SummaryGreater awareness of menstrual hygiene among girls is encouraging, but gaps in education, access, and stigma remain, making comprehensive period education essential for healthy practices.
Are Girls Today More Aware Of Period Hygiene? Why Education Still Matters

Credit: AI

Period hygiene is something that girls today are more aware of. This is because they have access to a lot of information from schools, doctors, social media and public health campaigns.

People are now more open to talking about periods than they were a years ago. Knowing about period hygiene does not always mean that girls are doing things the right way.

A lot of girls are still not sure how often they should change their sanitary pads or how to keep themselves clean. They also do not know which menstrual product is best for them.

Educating Young Girls About Menstruation

This is where parents can help. They should start teaching girls about menstruation before they get their period. This way girls will know that getting their period is not something to be scared of.

Parents should tell girls to change their sanitary pads every hour even if they are not completely soaked. They should also teach girls to wash themselves with clean water. Using soaps or fragrances is not necessary and can be bad for the skin.

When it is raining and the air is damp girls should keep themselves dry by patting themselves after washing. Wearing cotton underwear that can absorb moisture is also a good idea. This can help prevent infections.

Parents should also talk to girls about how to use menstrual products safely. Whether a girl uses sanitary pads, tampons, menstrual cups or period underwear she should know how to use them clean them and replace them correctly. If girls do not use these products the way they can get infections or feel uncomfortable.

Also read: Bryan Johnson's New 2.6M Women's Health Project Centers on Girlfriend's Menstrual Blood

Menstrual Products

There are different menstrual products available today. This is a thing because girls can choose the products that are best for them. Having so many options can also be confusing especially for teenagers.

Instead of saying that one product is better than another we should focus on making sure girls have all the information they need to make good choices.

All menstrual products are safe if used correctly. Girls should feel like they can try products ask for help when they need it and choose the products that make them feel good, about themselves.

By Dr Nishita Shah, Gynaecologist, Saifee Hospital

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