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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From Insulin Resistance to Fertility: Understanding the Metabolic Side of PCOS

Updated Sep 3, 2026 | 01:08 PM IST

SummaryPCOS can involve insulin resistance and metabolic changes that affect hormones, ovulation and fertility, making metabolic health an important part of managing the condition.
From Insulin Resistance to Fertility: Understanding the Metabolic Side of PCOS

Credit: AI

For many women, polycystic ovary syndrome (PCOS) begins with a familiar story—irregular periods, acne, unwanted hair growth or difficulty conceiving. But PCOS is far more than a reproductive disorder. At its core, it is often a complex interplay between metabolism, hormones and reproductive health.

One of the most important, yet frequently overlooked, pieces of this puzzle is insulin resistance. When the body becomes less responsive to insulin, the pancreas compensates by producing more.

Elevated insulin levels can, in turn, contribute to increased androgen production by the ovaries and disrupt the delicate hormonal signals required for regular ovulation. The result may be irregular cycles, fewer ovulations and, for some women, difficulty becoming pregnant.

PCOS And Insulin Resistance Can Affect Women Of Any Weight

Importantly, PCOS and insulin resistance are not synonymous with obesity. Women with a healthy body weight can also have significant metabolic abnormalities. This is why judging metabolic health by appearance alone can be misleading.

The 2023 International Evidence-based PCOS Guideline recognises insulin resistance as an important underlying feature and recommends attention to metabolic risk across the weight spectrum.

Also read: Decoding The Fertility Markers

The Metabolic Risks Go Beyond Fertility

The metabolic implications extend well beyond fertility. Women with PCOS have a higher risk of impaired glucose tolerance and type 2 diabetes, making long-term metabolic surveillance an important part of care.

The guideline recommends appropriate glycaemic assessment, particularly when pregnancy is being planned or fertility treatment is being considered.

Also read: Can Regular Consumption of Junk and Processed Food Affect Fertility?

Building A Healthier Foundation For Pregnancy

Yet there is an equally important message of hope: PCOS does not mean infertility, nor does it have to define a woman’s health journey. Lifestyle interventions—including regular physical activity, nutritious eating, adequate sleep and sustainable weight management where appropriate—form the foundation of care and can improve metabolic health.

For a woman planning pregnancy, the goal should not simply be to “get pregnant.” It should be to enter pregnancy metabolically and emotionally healthier, with blood sugar, blood pressure, nutrition, lifestyle and other risk factors appropriately addressed.

Take-home message: PCOS is not merely about irregular periods or cysts on the ovaries. It is a lifelong condition in which metabolic health and reproductive health are deeply connected. Recognising insulin resistance early, looking beyond weight, and providing personalised care can help women protect both their fertility today and their health for years to come.

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How An Inactive Lifestyle Is Damaging Your Knees

Updated Sep 3, 2026 | 09:56 AM IST

SummaryKnees are created for motion, and motion is essential for keeping the flexibility of a joint. The less active various leg muscles are, including quadriceps and other counterparts, the weaker they will be.
How An Inactive Lifestyle Is Damaging Your Knees

Credit: iStock

The view generally is that the occurrence of knee issues is usually associated with age, injury or overexertion. However, there is another reason people ignore: lack of movement. If a person leads an inactive lifestyle, spending long hours sitting at a desk, working from the couch, watching TV or doing nothing physical, the eventual consequences for the knees might arise.

Knees are created for motion, and motion is essential for keeping the flexibility of a joint. Their effective functioning depends on the health of the muscles surrounding your knee. The less active various leg muscles are, including quadriceps and other counterparts, the weaker they will be. The muscles help stabilize the knee and can relieve it from some of the burdens during daily activities performed by the knees.

Remaining seated for an extended time can also lead to stiffness. When you sit for a while, you may feel uncomfortable or stiff in your knees when you finally stand up. While the occasional instance of stiffness may go away with movement, constant stiffness can impact mobility and cause people to wish to move even less.

Another issue is gaining weight. Living a sedentary lifestyle causes individuals to become heavier, and excess weight puts more stress on the knees. In time, this added pressure will lead to increased wear of the joints and the development of knee pain and other problems in the musculoskeletal system.

The positive aspect with respect to your knees is that you don’t have to put in hours at the gym to keep them safe. Small, steady efforts can easily do the trick. You can choose to walk for five minutes after being seated for a long time, stretch regularly, take stairs if you are physically able and do some simple workouts for the legs and thighs to increase strength. Low-impact sports such as swimming, cycling and walking can help you maintain muscle power and flexible joints while avoiding the stress on your knees resulting from extensive workouts.

Persistent pain in the knee, however, cannot be treated as a usual symptom of ageing. Knee swelling or prolonged stiffness, difficulties climbing stairs, instability, or pain that has an impact on routine activities should be addressed by health professionals.

Movement is necessary for knees to be strong and flexible. Therefore, if you want your knees to be strong, you need to use them consistently and perform all activities without remaining still for long.

(By Dr Sujoy Bhattacharjee, Chairman & Chief, Max Institute of Robotic Joint Replacement, Max Super Speciality Hospital, Saket)

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Blocked Ears After Flight Turned Out To Be Rare Head And Neck Cancer In 22-Year-Old

Updated Sep 2, 2026 | 09:23 PM IST

SummaryAida Burkins from California was diagnosed with nasopharyngeal carcinoma, a rare type of head and neck cancer that starts in the upper part of the throat behind the nose and near the base of the skull.
Blocked Ears After Flight Turned Out To Be Rare Head And Neck Cancer In 22-Year-Old

Credit: TikTok

Blocked ears are one of the most common and irritating problems associated with air travel.

While the sensation usually resolves on its own shortly after landing, for 22-year-old Aida Burkins from California, it persisted and eventually led to a frightening diagnosis of rare head and neck cancer.

Blocked Ears Persisted After Flight

Burkins was travelling to Chicago in May 2025 when her ears became blocked. When she returned home, her ears still hadn’t popped.

She later developed unusual symptoms, including hearing loss and bleeding from her throat.

“I started bleeding into my throat, which would only come out of my nose if I was bent at the hip at about 90 degrees,” the 22-year-old told Newsweek. “My hearing got worse and worse. Then I started getting more tired and losing weight.”

Symptoms Were Initially Dismissed

When Burkins sought medical help, her condition was initially dismissed as “just altitude sickness.” After several months, her hearing had deteriorated significantly.

“Everything sounded so muffled, and I had a ringing that wouldn’t go away,” she said.

Burkins eventually saw an ear, nose, and throat (ENT) specialist, who discovered a mass and noted that her adenoids — soft tissue in the throat, just behind the nose — were inflamed.

“The doctor told me he had never seen anything quite like what I had going on. He couldn’t be sure it was cancer, but he said it was very suspicious,” she told the outlet.

Diagnosed With Rare Head And Neck Cancer

In February 2026, after undergoing CT scans and two biopsies, Burkins learned that she had a widespread tumour affecting the cervical lymph nodes near the base of her skull.

She was diagnosed with nasopharyngeal carcinoma, a rare type of head and neck cancer that starts in the upper part of the throat behind the nose and near the base of the skull, according to the American Cancer Society.

“Hearing I have cancer, all I thought about was not being able to see my babies grow up or do the things they want to do in life. It was horrifying,” Burkins, who is a mother to a 1-year-old and 3-year-old.

Burkins has since undergone months of chemotherapy and radiation. She is now finishing her treatment and hopes to be cancer-free soon as her body is responding well to the treatments.

What Is Nasopharyngeal Carcinoma?

According to the Mayo Clinic, nasopharyngeal carcinoma is a cancer that starts as a growth of cells in the nasopharynx, the upper part of the throat located behind the nose.

The cancer is rare in the United States and occurs much more often in other parts of the world, particularly Southeast Asia.

Nasopharyngeal carcinoma can be difficult to detect early because the nasopharynx is not easy to examine and there may be no symptoms initially.

Symptoms To Watch For

When symptoms do occur, they present non-classic signs which include:

  • A lump in the neck caused by a swollen lymph node
  • Nosebleeds
  • Bloody saliva
  • Double vision
  • Ear infections
  • Facial numbness
  • Headaches
  • Hearing loss
  • Nasal stuffiness
  • Ringing in the ears, known as tinnitus
  • Sore throat

How Is It Treated?

Treatment for nasopharyngeal carcinoma usually involves radiation therapy, chemotherapy, or a combination of the two, depending on the cancer and the individual patient.

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