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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Oncologist Answers: Can Heating Food In Black Plastic Bowls Give You Cancer?

Updated Apr 26, 2026 | 01:00 PM IST

SummaryBlack plastic containers have 'carbon black,' which, upon heating, releases toxic, cancer-causing chemicals.
black containers

Take-out food often comes in black plastic containers, but these are far from safe for your health. (Photo credit: iStock)

Plastic containers have been discouraged for a long time now, especially for heating food or storing hot food. Studies have associated this habit with a heightened risk of cancer, but now an expert has specifically spoken about black plastic containers and what makes them worse for you. According to Dr Rakesh Kumar Sharma, Senior Consultant Medical Oncologist at M | O | C Cancer Care & Research Centre, Gurugram, cooking or heating food in black containers could be very harmful to your body. Read on to find out how.

Dr Sharma, in an interview with Health and Me, said that cooking food in black plastic receptacles could lead to greater amounts of certain chemicals making their way into your body; however, there currently exists no scientific evidence confirming that this daily activity increases your risk of cancer.

Why is black plastic worse than others?

Dr Sharma explained that black takeaway containers usually consist of recycled plastics, such as e-waste, and can contain flame retardants, BPA, phthalates, etc. When heated in contact with food, especially if the food is hot, fatty, or acidic, more chemicals could potentially make their way into the food from the container. In this way, it may, over time, heighten your risk of developing a malignant tumour.

Black containers are coloured using carbon black, which is included in Group 2B of possible human carcinogens according to IARC, as shown in both animal and limited human research. Moreover, recycled black plastics could contain polycyclic aromatic hydrocarbons and decaBDE, which have shown carcinogenic effects in experiments. This makes black plastic containers worse than other coloured counterparts. Yet, heating food in a plastic container of any colour is not deemed safe.

Do studies verify the side effects of heating food in plastic containers?

Experimental studies conducted in laboratories on microwaveable plastic receptacles reveal the migration of tens of chemicals and millions of microplastics per litre of the food simulant. However, a recent study in 2024 reported that containers labelled as microwave-safe in Korea adhered to contemporary safety standards for these levels, and total exposure fell within safe limits.

Leading cancer associations have confirmed that the usage of plastic packaging, even in microwave applications, has not been linked with increased cancer risks in humans, although there is ongoing research in areas such as black plastics. However, precautionary measures are suggested by experts as a better strategy due to the difficulties of directly studying long-term, low-level exposure to chemical compounds.

How to reduce cancer risk?

When it comes to reducing cancer risk, most doctors recommend quitting smoking and limiting alcohol intake. However, Dr Sharma listed some basic kitchen and eating habits that may come to your rescue:

  1. Avoid cooking food in black plastic packaging, particularly if the food is oily or acidic.
  2. Move hot food into glass, ceramic, or stainless steel containers for reheating.
  3. Only use microwave-safe containers and discard any broken plastic containers.

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Decoding Depression In Men: The Emotion Behind The Silence

Updated Apr 26, 2026 | 05:00 PM IST

SummaryOne of the key barriers in identifying depression in men is the way emotional awareness is shaped from an early age. Many men are conditioned to respond to discomfort through action rather than reflection.
Decoding Depression in Men: The Emotion Behind The Silence

Credit: iStock

Depression in men often does not look like the depression we all know about. It is never visible sadness or a verbal expression of emotional pain. The emotional dish is missing from the life menu of a man.

It hides behind productivity, irritability, exhaustion, or strong discipline. This masking makes it the most underdiagnosed mental health concern, frequently misread as stress, burnout, or simply personality traits.

One of the key barriers in identifying depression in men is the way emotional awareness is shaped from an early age. Many men are conditioned to respond to discomfort through action rather than reflection.

The moment something feels overwhelming, the instinct is not to sit with the feeling but to fix it, outperform it, or suppress it through movement—work, exercise, or distraction.

While this can provide short-term relief, it often delays emotional processing and deepens internal distress over time.

Clinically, this disconnect is often linked to alexithymia—a difficulty in identifying and articulating emotions.

The emotional signal is present, but it does not translate easily into words. Instead of “I am sad” or “I feel afraid,” the experience gets reduced to “I am tired” or “I am stressed.”

This limited emotional vocabulary can significantly affect help-seeking behavior like therapy and counselling, as the man does not recognize the depth or nature of what they are experiencing.

Depression In Men: Poor Physical Health

From a health perspective, unresolved emotional stress is not limited to the mind. It reflects in the body.

Chronic fatigue, sleep disturbances, headaches, digestive issues, and muscle tension are some of the symptoms seen.

Men who are very aware tend to see general physicians and not go to mental health professionals, treating physical symptoms while the psychological root remains unattended to.

Another way is externalized emotion. Irritability, anger outbursts, or risk-taking behaviour are often socially accepted expressions of underlying emotional pain.

A man working excessively, exercising compulsively, or withdrawing socially may, in fact, be coping with grief, loneliness, or anxiety, which are socially normal.

Our culture around masculinity complicates diagnosis even more. Strength is seen with emotional control, and vulnerability is seen as weakness.

Most men do not seek psychological support until symptoms become severe or functionally impairing. They struggle to express their internal state, reinforcing the cycle of silence.

Depression In Men: Physiological Indicators

Understanding depression in men requires shifting the lens from visible sadness to behavioral and physiological indicators.

It requires mental health practitioners and caregivers to look beyond surface functionality and recognise that high performance can coexist with deep emotional distress.

Early intervention is very important. Creating environments where emotional language is normalised without judgement or immediate problem-solving can significantly improve the situation. When men are given consistent permission to articulate internal states without fear of stigma, the gap between emotional experience and expression begins to close.

“Expressing your feelings should lead to a deeper connection, not conflict. It should invite empathy, not ego-driven reactions. It should bring relief, not retaliation or emotional punishment. If sharing your pain feels unsafe or punished, you are not in a healthy relationship—you are in an emotional environment where fear has replaced trust.”

Depression in men is not a lack of feeling, but a lack of translation. True healing begins when that translation is finally allowed to happen.

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No Pain, No Problem: Oncologist Debunks A Common Myth About Testicular Health

Updated Apr 26, 2026 | 09:00 AM IST

SummaryPainless lumps are a key early sign of cancer and must never be overlooked.
Testicular health

Young men must go for regular health check-ups to rule out the possibility of health problems later.

Most young men assume that if there is no pain, there is no serious problem. Unfortunately, many important testicular conditions, especially testicular cancer, often begin as a painless lump, swelling, or enlargement of one testicle. Because there is no pain, men tend to ignore it, thinking it is due to exercise, minor trauma, tight clothing, cycling, or temporary swelling. Embarrassment and reluctance to discuss genital symptoms also contribute to delay.

Dr. Chandan M. N, Consultant Urologist, Andrologist, Uro-Oncologist & Renal Transplant Surgeon, Apollo Hospitals, Sheshadripuram, Bangalore, spoke about the pain conundrum. The expert said that when it comes to testicular health, absence of pain must not be a reassuring factor.

Pain is usually seen as a warning signal, but in testicular disease, absence of pain should not reassure patients. Testicular cancer is one of the most common cancers in young men, particularly between 15 and 35 years of age, and it can progress quickly if diagnosis is delayed. However, when detected early, it is also one of the most curable cancers.

What are the common signs men may overlook in day-to-day life?

The most commonly overlooked sign is a painless lump or swelling in one testicle.

Sometimes the change is subtle; a testicle may simply feel slightly harder, heavier, larger, or firmer than before. Many men also ignore a dragging sensation, heaviness in the scrotum, or a dull ache in the groin or lower abdomen because these symptoms are mild and not severe enough to disrupt daily life.

Other signs that should not be ignored include sudden fluid collection in the scrotum, change in the shape or size of one testicle, unevenness between the two testicles, persistent discomfort, or a feeling that something is different. Some men may also notice back pain, breast tenderness, or unexplained swelling if the disease has spread. Importantly, not every testicular lump is cancer. Conditions such as hydrocele, varicocele, spermatocele, orchitis, or hernia can also present with swelling or heaviness. But the only safe approach is to get examined rather than assume it is harmless.

How to do a simple self-examination at home?

Young men should know what is normal for their own body. A simple self-examination once a month, ideally after a warm shower when the scrotal skin is relaxed, can help detect early changes.

Men should gently feel each testicle for lumps, swelling, hardness, change in size, or heaviness. Familiarity with one’s normal anatomy makes it easier to notice when something changes. Any new lump, swelling, change in shape, or persistent discomfort should be evaluated promptly by a doctor. Usually, a physical examination and scrotal ultrasound are enough to identify the cause. Early medical advice can differentiate a harmless condition from something serious and, in the case of testicular cancer, can make the difference between simple treatment and advanced disease.

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