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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Obesity-Driven CKM Syndrome A Growing Public Health Threat, Warns American Heart Association

Updated Jul 10, 2026 | 10:03 AM IST

SummaryNearly 9 in 10 adults in the United States have at least one condition associated with CKM syndrome. These include high blood pressure, abnormal cholesterol and other lipid disorders, high blood sugar, reduced kidney function and excess body weight.
Obesity-Driven CKM Syndrome A Growing Public Health Threat, Warns American Heart Association

Credit: iStock

Cardiovascular-kidney-metabolic (CKM) syndrome is emerging as a major public health threat, according to new guidelines from the American Heart Association (AHA), which identify obesity as a key driver of the condition's development and progression.

The guidelines, jointly issued by the AHA and the American College of Cardiology (ACC), reframe excess weight as more than a number on the scale, describing it as a significant health risk closely linked to diabetes, chronic kidney disease and cardiovascular disease.

According to the AHA, nearly 9 in 10 adults in the United States have at least one condition associated with CKM syndrome. These include high blood pressure, abnormal cholesterol and other lipid disorders, high blood sugar, reduced kidney function and excess body weight.

With obesity rates continuing to rise, the guideline urges healthcare professionals to have prevention-focused conversations with patients about maintaining a healthy weight to reduce the risk of future heart, kidney and metabolic diseases.

“CKM syndrome is a real, rising public health threat,” said Chiadi E. Ndumele, an American Heart Association volunteer and chair of the writing committee for the new guideline.

“In terms of CKM health, weight is not just about a number on a scale — people with the same body weight can have very different health profiles. Rather, what’s most important is how fat tissue affects your metabolic health. This includes how your body manages blood sugar levels and how fat is used and stored,” Ndumele, who is also director of obesity and cardiometabolic research at Johns Hopkins University in Baltimore.

The New CKM Syndrome Guideline

Also read: Bryan Johnson's Autoimmune Gastritis: US Doctor Explains the Hidden Signs of Autoimmune Disease

The updated guideline replaces the 2013 recommendations for managing overweight and obesity. CKM syndrome itself was first formally defined by the American Heart Association in 2023.

The guideline highlights several strategies to improve the prevention and treatment of CKM syndrome:

  • Use the Predicting Risk of Cardiovascular Disease EVENTs (PREVENT) equations to estimate 10-year and 30-year cardiovascular disease risk. Unlike previous tools, PREVENT incorporates kidney and metabolic health factors for a more comprehensive risk assessment.
  • Screen patients for social determinants of health, including food insecurity, housing instability and financial strain, which can increase the risk of CKM syndrome.
  • Promote coordinated, multidisciplinary care focused on healthy lifestyle behaviors, including physical activity, nutrition, weight management, blood pressure control, blood sugar management and cholesterol reduction.
  • Alongside lifestyle interventions, use medications and surgical therapies when appropriate to manage blood pressure, cholesterol, blood sugar and obesity while protecting heart and kidney health.
  • For the first time, the guideline recommends GLP-1-based therapies for select individuals with obesity and/or Type 2 diabetes who are at elevated cardiovascular risk. Metabolic and bariatric surgery is also recognised as an effective treatment option for eligible patients.

How Can CKM Syndrome Be Prevented?

Read More: Are You Getting The Right Cholesterol Test? ApoB May Be Better Than LDL

The guideline emphasizes that early lifestyle changes can significantly reduce the risk of heart attack, heart failure, stroke and kidney failure.

People are encouraged to follow the AHA's Life's Essential 8, which promotes

  • regular physical activity,
  • a heart-healthy diet,
  • maintaining a healthy weight,
  • controlling blood pressure,
  • maintaining blood sugar
  • better cholesterol control,
  • avoiding tobacco,
  • getting sufficient quality sleep.

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Monsoon Playbook for Parents: Common Home Mistakes That Increase Infection Risk in Children

Updated Jul 10, 2026 | 07:05 AM IST

SummaryMany families keep doors and windows closed throughout the day to prevent rainwater from entering the house. However, limited air circulation can lead to the growth of mold, dampness, and indoor allergens, which may trigger respiratory infections.
Monsoon Playbook for Parents: Common Home Mistakes That Increase Infection Risk in Children

Credit: AI generated image

The monsoon brings welcome relief from the heat, but it also creates conditions that make infections spread more easily among children. Parents should understand that a few common household mistakes can increase the risk of illness in children during this time of year. So, parents must exercise caution and take utmost care of their children during those rainy days.

Why Monsoon Raises Infection Risk in Children

The arrival of the monsoon often means more time spent indoors for children, muddier surroundings, and increased exposure to germs. So, the main focus of parents is on protecting their children from rain and cold weather. However, parents must understand that certain everyday habits at home may unknowingly increase the risk of respiratory infections, stomach illnesses, and mosquito-borne diseases.

Common Mistakes Of Infections In Children

So, many children can get drenched during those heavy rains and remain in wet clothes or footwear for long periods after returning from school or outdoor activities. Damp socks and shoes can create an environment where germs and fungal infections thrive. Parents should ensure that children change into dry clothes and footwear as soon as possible. Moreover, stagnant water collected in flower pots, buckets, coolers, balconies, and outdoor containers can become breeding grounds for mosquitoes, raising the chances of dengue, malaria, and chikungunya in children.

Many families keep doors and windows closed throughout the day to prevent rainwater from entering the house. However, limited air circulation can lead to the growth of mold, dampness, and indoor allergens, which may trigger respiratory infections, coughing, wheezing, and allergies in children. Even having uncovered food, improperly stored leftovers, or contaminated water can increase the risk of stomach infections, diarrhea, vomiting, and food poisoning in children.

Tips Parents Should Follow During the Monsoon

Parents should ensure that the child changes wet clothes, socks, and shoes immediately after returning home. Parents should empty and clean containers that can collect stagnant water from time to time. Use mosquito nets, screens, and child-safe mosquito repellents to prevent mosquito bites. Keep rooms well ventilated whenever the weather permits. The child should follow good hand and personal hygiene, eat freshly cooked food, and drink safe drinking water.

The parents should ensure to wash fruits and vegetables thoroughly before consumption. The child should eat a nutritious diet, sleep well, and stay hydrated to boost immunity and prevent any illness. Parents should seek immediate help if the child is having any symptoms, such as a cough or allergies, and follow the expert's guidelines. Parents should not give any medication to the child on their own without the doctor's knowledge. So, parents should stay alert during the monsoon and help the child stay healthy.

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Bryan Johnson's Autoimmune Gastritis: US Doctor Explains the Hidden Signs of Autoimmune Disease

Updated Jul 9, 2026 | 09:53 PM IST

Summary​According to the Centers for Disease Control and Prevention (CDC), autoimmune diseases occur when the immune system mistakenly attacks the body's own healthy cells and tissues, triggering inflammation and damage to organs or other body systems.
Bryan Johnson's Autoimmune Gastritis: US Doctor Explains the Hidden Signs of Autoimmune Disease

Credit: iStock/Instagram

Billionaire entrepreneur Bryan Johnson, known for meticulously tracking his health and pursuing longevity, recently revealed that he has been diagnosed with Autoimmune Gastritis, an incurable autoimmune condition in which the body's immune system attacks the stomach lining.

Describing the disease on social media platform X, Johnson said: "My stomach is eating itself." He also noted that despite undergoing extensive medical evaluations over the years, the condition went undetected because autoimmune diseases often develop quietly, with symptoms that can easily be mistaken for everyday health issues such as fatigue or digestive discomfort.

According to the Centers for Disease Control and Prevention (CDC), autoimmune diseases occur when the immune system mistakenly attacks the body's own healthy cells and tissues, triggering inflammation and damage to organs or other body systems.

The burden of these conditions is significant. In May 2025, researchers from the Mayo Clinic and collaborating institutions estimated that nearly 15 million Americans are living with one or more of 105 recognized autoimmune diseases.

Symptoms Can Be Easy to Miss

Because autoimmune diseases often begin with vague, non-specific symptoms, they can remain undiagnosed for months—or even years.

Dr. Cory Rice, a US-based Functional Medicine physician, said these warning signs frequently go unnoticed until the disease has progressed.

"First and foremost, symptoms of autoimmune disease can come and go, and be on and off, or they can be more persistent in nature," he told Newsweek.

Also read: Paxlovid Safe for Children Aged 6 And Older, New Study Finds

The Hidden Signs You Shouldn't Ignore

While symptoms vary depending on the various autoimmune conditions, several early warning signs are shared across many autoimmune diseases.

According to Dr. Rice, common symptoms include:

  • Fatigue
  • Low-grade fever
  • Joint pain
  • Unexplained rashes or hives
  • Dry eyes and dry mouth
  • Numbness or tingling in the hands or feet
  • Mouth ulcers
  • Increased sensitivity to cold temperatures

He said when people suffer from fatigue, "it is usually both profound and debilitating."

Dr. Rice explained that many people try to manage this overwhelming exhaustion by relying on caffeine and other stimulants, taking thyroid medications or hormone treatments, or opting for therapies such as intravenous infusions and vitamin B12 injections.

However, when an underlying autoimmune disease is responsible, these approaches often fail to provide lasting relief.

Read More: Can Arsenic, Lead and Other Metals In Tampons Pose A Health Risk? FDA Says No

Why Autoimmune Diseases Are Often Diagnosed Late

One of the biggest challenges in diagnosing autoimmune diseases is that their symptoms overlap with those of many other medical conditions.

Johnson also said that "2-5 per cent of people have this (autoimmune disease). Likely more, because it hides".

Symptoms may also appear intermittently before becoming more persistent.

"It all depends on the disease process in play and the severity or progression of the disease itself in a particular person as to whether symptoms are more constant or intermittent," Rice said.

He added that many primary care physicians are not routinely trained to identify autoimmune diseases in their early stages. As a result, patients are frequently referred to specialists, including rheumatologists, only after symptoms have become more pronounced.

"Unfortunately, by this point, the autoimmune disease may already be far along in whichever parts of the body are impacted," he said.

Dr. Rice emphasized that recognizing symptoms early and obtaining a timely diagnosis can help slow disease progression and improve long-term outcomes.

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