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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AIIMS Performs Second Dual Kidney Transplant Using Organs From 70-Year-Old Donor: How It Can Expand Donor Pool?

Updated Aug 9, 2026 | 03:00 PM IST

SummaryAIIMS New Delhi recently announced that it performed a its second dual kidney transplant using organs from 70-year-old donor. This marks a milestone in expanding donor pool.
AIIMS Performs Second Dual Kidney Transplant Using Organs From 70-Year-Old Donor: How It Can Expand Donor Pool?

Credit: AI

AIIMS New Delhi has successfully performed its second dual kidney transplant using organs from a marginal donor. The procedure highlighted a strategy that could help make greater use of kidneys that may otherwise be rejected for transplantation.

The procedure was carried out on July 28 by a multidisciplinary team from the Departments of Surgical Disciplines, Nephrology, Anaesthesia, Transplant Immunology and the Organ Retrieval Banking Organisation (ORBO).

The donor was a 70-year-old woman from Command Hospital, Chandimandir, Chandigarh. Because of her advanced age and the marginal characteristics of the donated kidneys, doctors transplanted both kidneys into a single 56-year-old woman.

The organs were transported from Chandigarh to New Delhi by an Army helicopter. According to AIIMS, despite a cold ischaemia time of 12 hours, both kidneys were functioning immediately after transplantation.

The recipient showed no complications after the transplantation and was discharged after 10 days with normal kidney function.

What Is A Dual Kidney Transplant?

In a conventional kidney transplant, one donated kidney is transplanted into a recipient. Meanwhile, in a dual kidney transplant both kidneys are placed into one patient from the same deceased donor.

The approach is considered when the donor is older or the kidneys have characteristics that suggest that a single kidney may not provide sufficient function.

In simple terms, two kidneys that have lower individual functional capacity may be able to provide adequate overall kidney function when transplanted together.

Research has previously found that dual kidney transplantation can be a viable option for kidneys from older or marginal donors. Transplant teams carefully assess the donor organs and recipient before deciding whether using both kidneys together could provide adequate renal function.

A 2025 analysis comparing single and dual transplantation from marginal donors also highlighted the potential of using kidneys from a deceased donor.

Also read: The Hidden Cost Of Self-Medicating UTIs. How Antibiotic Misuse Is Fueling Resistance

Need Of The Hour

The milestone comes as India faces shortage of transplantable organs. India recorded 20,138 organ transplants in 2025, crossing the 20,000 mark for the first time, but the number of patients needing transplants remains far higher than the available organs.

Recent reports has also highlight the country's mounting transplant needs that still remain unmet despite its position as one of the world's largest transplant centres by volume.

This makes the ability to safely use organs from older or marginal donors particularly important.

“Dual kidney transplantation from carefully selected marginal donors represents an important strategy for increasing the utilization of deceased-donor organs,” AIIMS said in the press release.

AIIMS said the successful transplant demonstrates its efforts to “maximize the utilization of marginal donor organs” and help patients with end-stage kidney disease receive organs at the earliest.

Also read: US HHS Action Against Kentucky Organ Donation Group Raises Questions About Transplant Safety

Encouraging Development

The immediate functioning of both kidneys despite around 12 hours of cold storage is certainly encouraging. However, the patient’s discharge with normal kidney function represents an early outcome.

Longer follow-up will be needed to determine how well the transplanted kidneys perform over the months and years ahead.

The AIIMS team was led by Prof. Asuri Krishna, with support from the nephrology, anaesthesia, transplant immunology, ORBO and organ retrieval teams.

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Post-Menopausal Women Face A Higher Risk Of Fatty Liver Disease: How Falling Oestrogen Levels Impact Liver Health

Updated Aug 9, 2026 | 01:00 PM IST

SummaryFalling oestrogen levels after menopause may increase women’s risk of fatty liver disease by affecting fat distribution, metabolism, and liver health, highlighting the importance of early prevention.
Post-Menopausal Women Face A Higher Risk Of Fatty Liver Disease: How Falling Oestrogen Levels Impact Liver Health

Credit: AI

It is a common belief that metabolic dysfunction-associated steatotic liver disease (MASLD)—formerly known as non-alcoholic fatty liver disease (NAFLD)—is primarily associated with diet, sedentary lifestyles, and obesity. However, there are other factors as well affecting this aspect. Post-menopausal women experience a significantly higher incidence and faster progression of fatty liver disease, even when maintaining a stable body weight.

Why Menopause Increases Fatty Liver Risk

In pre-menopausal women, oestrogen plays a central role in metabolism, by promoting healthy fat accumulation in subcutaneous tissue (below the skin) rather than around internal organs, it also increases insulin sensitivity and suppresses liver inflammation.

After menopause when oestrogen levels drop, this protective function is lost, there is redistribution of fat leading to more fat accumulation around internal organs including liver thus leading to increase chances of NAFLD and also increasing insulin resistance, needless to say that with age our metabolic rate also goes down which also plays a role in this.

Also read: Decoding The Fertility Markers

Early Detection Is Key

The important part lies not only in understanding above but to go further in early detection and prevention of menopause associated NAFLD. As we know that fatty liver is a silent disease and often does not causes any signs and symptoms till very advanced stage.

First and foremost is to change lifestyle with advancing age, changing both the dietary habits and physical activity. Regular screening and monitoring is warranted with blood tests, routine metabolic panels, keeping a tab on weight, sugar and cholesterol levels and a basic ultrasound of abdomen.

For someone already diagnosed with 2nd or 3rd stage fatty liver, a simple non-invasive. Fibroscan can help monitor and assess the response to treatment.

Also read: How Menopause Changes Heart Health Risks?

Understanding The Impact Of Menopause On Liver Health

Coming to treatment part of NAFLD in post-menopausal women, it being primary a lifestyle disease so the core of management also lies around managing lifestyle. Medicines are available for treating and controlling NAFLD in conjunction with lifestyle management.

Hormone replacement therapy (HRT), when initiated early in post-menopausal women for symptomatic relief may offer secondary benefits by maintaining metabolic health. However HRT should always be initiated after proper evaluation and expert guidance.

NAFLD is a silent epidemic and primarily a life style disease, knowing about it and knowing triggering and precipitating factors helps understanding and prevention better.

Menopause being a natural biological phenomenon in every female’s life, it becomes essential for us to know how it affects our liver health and overall health as well.

By Mr. Ankur Garg, Group Director Liver Transplant & GI Surgery, Paras Health, Gurgaon

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Monsoon Gut Health: Addressing The Rise In Rotavirus And Viral Gastroenteritis Cases

Updated Aug 8, 2026 | 11:00 PM IST

SummaryMonsoon conditions can increase the spread of rotavirus and viral gastroenteritis, making safe food, clean water, hand hygiene, and timely care important for preventing gut infections.

Credit: AI

Every year, as the monsoon rolls in, hospitals and clinics across India see a familiar pattern: a sharp uptick in children and elderly patients presenting with vomiting, diarrhoea, and dehydration.

Doctors attribute this seasonal surge to a combination of contaminated water supplies, deteriorating food hygiene, and warm, humid conditions that favour the spread of viruses like rotavirus and norovirus.

Why Monsoon Fuels Gut Infections

Heavy rains and flooding routinely compromise municipal water lines, allowing sewage to mix with drinking water. Street food and produce are more prone to contamination during this period, and the humidity itself accelerates bacterial and viral growth.

Acute gastroenteritis, an inflammation of the stomach and intestines, is consistently one of the fastest rising monsoon health conditions, with rotavirus being a leading cause in children and norovirus a common culprit across age groups.

Understanding Rotavirus

Rotavirus is a highly contagious, wheel shaped virus and remains the leading cause of severe diarrhoeal illness and death in children under five worldwide. It spreads through the faecal oral route via contaminated water, food, surfaces, or close contact with an infected person, and can cause several days of intense vomiting and watery diarrhoea, putting young children at real risk of rapid dehydration.

The good news: Rotavirus vaccines, given orally in a series of doses before 8 months of age, are highly effective at preventing severe disease and are recommended as part of national immunisation programmes.

Also read: Climate Change And Progressive Urbanization Call For An Integrated Approach To Infectious Disease Surveillance

Expert Recommended Prevention Measures

1. Water safety first

Boil or filter all drinking water during the monsoon months. Avoid ice and beverages of uncertain origin, especially from street vendors.

2. Food hygiene

Steer clear of cut fruits, chaat, and other street food that has been sitting exposed. Cook food thoroughly and eat it hot. Avoid reheated leftovers stored without refrigeration.

Also read: Dengue & Guillain-Barré Syndrome: Can A Common Monsoon Illness Trigger A Serious Nerve Disorder?

3. Hand hygiene

Frequent handwashing with soap before eating, after using the toilet, and after changing diapers remains one of the single most effective, low cost interventions against faecal oral transmission.

4. Vaccination

Ensure infants complete their full rotavirus vaccine schedule on time. Vaccination substantially reduces hospitalisations and severe outcomes, even though it does not eliminate all seasonal transmission.

5. Isolate and disinfect

Because these viruses spread easily within households and childcare settings, keep infected individuals' utensils and linens separate, and disinfect surfaces regularly during an active infection.

Recognising The Warning Signs

Most cases of viral gastroenteritis are self limiting, but caregivers should watch for signs of dehydration that require urgent medical attention:

  • Sunken eyes, dry mouth, or reduced tears when crying (in infants)
  • Little or no urination for 6+ hours
  • Lethargy or unusual drowsiness
  • Persistent vomiting that prevents fluid intake
  • High fever or blood in the stool

Also read: Beware! Common Mistakes New Parents Make During Their Baby’s First Monsoon

Treatment: What Actually Helps

Oral Rehydration Solution (ORS) is the cornerstone of management.

A simple homemade version consists of 1 litre of boiled and cooled water, 6 teaspoons of sugar, and half a teaspoon of salt. It can be lifesaving when commercial ORS packets are not available, though pre mixed WHO formula ORS is preferable when accessible.

Zinc supplementation (around 20 mg daily for 10 to 14 days) is recommended for children under five, as it has been shown to reduce the duration and severity of diarrhoeal episodes.

Antibiotics are not effective against viral gastroenteritis and should only be used if a bacterial cause, such as cholera, is confirmed by a doctor. Inappropriate antibiotic use can do more harm than good.

Continue feeding. For breastfed infants, continue breastfeeding throughout the illness. For older children and adults, small, frequent sips of fluids and bland, easily digestible food are better tolerated than large meals.

When to See a Doctor

Seek medical care promptly if there is persistent high fever, visible blood in the stool or vomit, signs of moderate to severe dehydration, or if symptoms do not improve within 2 to 3 days, particularly in infants, the elderly, or anyone with underlying health conditions.

By Dr. Geeta Malkan Billa, Director of Gastroenterology & Hepatology at Dr. L. H. Hiranandani Hospital

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