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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GLP-1 Microdosing: People Are Experimenting With Weight Loss Drugs & What Do Experts Have To Say About It?

Updated Jul 27, 2026 | 09:00 PM IST

SummaryAs the number of Ozempic, Wegovy, and Mounjaro users has increased significantly, the viral trend of GLP-1 microdosing has raised concerns.
GLP-1 Microdosing: People Are Experimenting With Weight Loss Drugs & What Do Experts Have To Say About It?

Credit: AI

As GLP-1 medications such as semaglutide (Ozempic, Wegovy) and tirzepatide (Mounjaro, Zepbound) continue to help manage metabolic disorders and obesity, a new trend is rapidly gaining traction on social media - GLP-1 microdosing.

Instead of taking the prescribed doses approved for diabetes or obesity, some users are deliberately taking much smaller amounts, claiming they can lose weight, reduce food noise, avoid side effects, save money, or even improve longevity.

However, experts warn that there is currently little scientific evidence that GLP-1 microdosing is safe or even effective.

What Is GLP-1 Microdosing?

Some people reduce their dose by extending the time between injections, counting "clicks" on injection pens instead of using prescribed doses, or taking customized low-dose formulations.

HealthandMe spoke to Dr. Shehla Shaikh, Consultant Endocrinologist, Saifee Hospital, Mumbai, about the trend of GLP-1 microdosing.

Dr. Shaikh says, "The lowest dose that is supported by evidence for semaglutide is 0 25 mg. While, for tirzepatide, it is 2 5 mg Some people are using much smaller amounts for example using nine clicks on a semaglutide pen which gives about 0 06 mg. Now there are no randomized studies or clear guidelines that show if this kind of micro-dosing is safe or works."

Also read: Can GLP-1 Drugs Like Ozempic, Mounjaro Cause Hair Loss? Study Says It's Rare But Real

Medical experts caution that these practices fall outside approved prescribing guidelines and have not been rigorously studied.

The expert says, "One big worry is how accurate the dose is. These injectable pens are made to give set approved amounts; not amounts based on people counting clicks. Even a small mistake in counting can mean taking too little medicine which may not work well or too much, which could cause more problems. Since these instructions are complicated, they need careful handling good eyesight and understanding of the device."

Why Are People Trying It?

Fewer Side Effects

Lower Cost

These medications are expensive in various countries. So, people stretch a single prescription by taking less medication than prescribed.

Weight Maintenance

Rather than pursuing significant weight loss, some users say they simply want to maintain previous results or reduce constant food cravings without taking full doses.

Longevity Claims

Online influencers have begun promoting low-dose GLP-1s as potential "longevity drugs." While GLP-1 medications show promise for heart and metabolic health, experts stress that these benefits have only been demonstrated using clinically tested doses, not microdoses.

Also read: Novo Nordisk Sues Eli Lilly Over Weight-Loss Drug Ads: Should GLP-1 Users Be Concerned?

The Risks of Microdosing

Reduced Effectiveness

Taking too little medication may fail to adequately suppress appetite, improve blood sugar levels, or achieve meaningful weight loss.

Dr. Shaikh says, "People often choose microdosing because they want to avoid problems reduce appetite with a smaller dose or make a costly medicine last longer. While smaller amounts might help a bit, current information shows that the best and steadiest results come from following the approved ways to take the medicine. Using doses that are too low might not give the results to people who want to lose weight or manage their metabolic health."

Delayed Medical Treatment Or Risk Of Expiration

Experts also say that people with obesity or diabetes could unknowingly receive suboptimal treatment while believing they are protected. Another problem is how long the medicine lasts after it is opened.

Dr. Shaikh explains, "An opened semaglutide pen should be used within 60 days while an opened tirzepatide pen should be used within 30 days. Because microdosing uses the medicine over a longer time, people might keep using it past the time it is safe which could change how good it is."

Inaccurate Dosing

Also read: Could GLP-1 Weight Loss Drugs Help People Take Fewer Sick Days? New Study Says So

Some users manually estimate doses by counting injection pen clicks. Experts warn these devices are designed to deliver specific calibrated doses, making partial dosing unreliable.

The expert says, "Some people think micro-dosing gives similar benefits with fewer problems or lower costs, but this practice has no scientific support and might have several dangers."

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Doppler Test Explained: From Leg Pain to Pregnancy, When Do You Need One?

Updated Jul 27, 2026 | 04:12 PM IST

SummaryWhile commonly associated with pregnancy, Doppler ultrasound is also used to investigate conditions such as leg pain, swelling, varicose veins, blood clots, peripheral artery disease, and stroke risk.
Doppler Test Explained: From Leg Pain to Pregnancy, When Do You Need One?

Credit: iStock

A Doppler test is a specialized type of ultrasound that uses sound waves to measure blood flow through blood vessels rather than simply creating images of organs and tissues. Unlike a regular ultrasound, which produces pictures of internal structures, a Doppler ultrasound shows how blood moves through arteries and veins, helping doctors detect circulation problems.

While commonly associated with pregnancy, Doppler ultrasound is also used to investigate conditions such as leg pain, swelling, varicose veins, blood clots, peripheral artery disease, and stroke risk. Understanding when this test is needed can help detect serious conditions early and guide timely treatment.

Why Is Doppler Ultrasound Important During Pregnancy?

During pregnancy, a Doppler ultrasound is often recommended in high-risk cases to assess blood flow between the mother, placenta, and baby.

"It helps doctors monitor whether the fetus is receiving adequate oxygen and nutrients, making it especially important in pregnancies complicated by high blood pressure, diabetes, fetal growth restriction, or previous pregnancy-related complications," Dr. Vandana Mittal, Principal Consultant, Obstetrics and Gynecology, Paras Health Panchkula, told HealthandMe.

Dr. Vandana Jain, Principal Consultant - Obstetrics, Gynecology, Infertility & Advanced Laparoscopic Surgery, Yashoda Medicity, added that the test is commonly recommended in high-risk pregnancies, including fetal growth restriction, preeclampsia, hypertension, gestational diabetes, oligohydramnios, multiple pregnancies, and decreased fetal movements.

"By evaluating how effectively oxygen and nutrients are reaching the baby, the test helps detect signs of fetal compromise at an early stage, enabling timely monitoring, appropriate medical intervention, and informed decisions regarding the timing and mode of delivery."

By identifying potential issues early, Doppler studies help doctors monitor pregnancies more closely and intervene when necessary. However, the test is performed only for specific medical indications and is not a replacement for routine pregnancy ultrasounds.

What Other Conditions Can a Doppler Ultrasound Detect?

According to the Mayo Clinic, a Doppler ultrasound can help diagnose:

  • Blood clots
  • Venous insufficiency, where poorly functioning vein valves cause blood or fluid to pool in the legs
  • Heart valve defects and congenital heart disease
  • Arterial occlusion (blocked arteries)
  • Peripheral artery disease
  • Aneurysms
  • Carotid artery stenosis, which increases stroke risk

How Doppler Ultrasound Can Help People With Leg Pain

Dr. Jain said Doppler ultrasound is also commonly advised for patients with suspected Deep Vein Thrombosis (DVT), peripheral arterial disease, carotid artery narrowing, or chronic venous insufficiency.

"It is commonly advised for patients with suspected Deep Vein Thrombosis (DVT), peripheral arterial disease, carotid artery narrowing, or chronic venous insufficiency," she told HealthandMe.

The expert added that people with persistent leg pain while walking, unexplained swelling, non-healing wounds, or symptoms of poor circulation may require a Doppler evaluation.

Recently, gastroenterologist Dr. Pal Manickam highlighted the importance of Doppler ultrasound during a podcast discussion. He urged people not to ignore sudden leg pain or swelling, noting that these symptoms could indicate deep vein thrombosis (DVT) and require prompt evaluation.

How Is a Doppler Test Done?

The procedure is painless, non-invasive, and usually takes 30 to 60 minutes, depending on the area being examined. It is also radiation-free.

A Doppler ultrasound is performed by a trained sonographer using a hand-held device called a transducer. The transducer sends sound waves into the body and measures how they bounce off moving blood cells, allowing the machine to assess blood flow in real time.

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Prostate Cancer: NHS England's New Precision Radiotherapy Offers Hope In Just 5 Sessions

Updated Jul 27, 2026 | 05:00 PM IST

SummaryAccording to NHS England, stereotactic ablative radiotherapy (SABR) delivers highly targeted radiation to the tumor from multiple angles, helping reduce the risk of the cancer returning or spreading.
Prostate Cancer: NHS England's New Precision Radiotherapy Offers Hope In Just 5 Sessions

Credit: iStock

A new high-precision radiotherapy treatment introduced by NHS England is set to offer a faster and more convenient treatment option for thousands of men with prostate cancer.

Known as stereotactic ablative radiotherapy (SABR), the treatment delivers high-dose radiation in just five sessions over two weeks, compared with the 20 or more sessions typically required with conventional radiotherapy. This means eligible patients can complete treatment with 15 fewer hospital visits, reducing the burden of travel and time spent in care.

Prostate cancer is the most common cancer among men in the UK. More than 55,000 men are diagnosed with the disease each year, while around 12,300 die from it annually.

According to NHS Chief Executive Sir Jim Mackey, the new therapy will "transform" treatment for thousands of men with localized prostate cancer while enabling the NHS to provide "far more powerful and more convenient" cancer care.

How Does SABR Work?

According to NHS England, stereotactic ablative radiotherapy (SABR) delivers highly targeted radiation to the tumor from multiple angles, helping reduce the risk of the cancer returning or spreading.

The treatment delivers a higher dose of radiation with pinpoint accuracy, minimizing damage to surrounding healthy tissue and reducing the likelihood of side effects.

"This technology lets us focus a powerful and precise beam of radiotherapy directly onto the cancer, limiting the damage to healthy cells – and the fact it can be delivered in 15 fewer doses will help men get back to living their lives far more quickly," said Professor Peter Johnson, NHS National Clinical Director for Cancer.

Also known as stereotactic body radiotherapy (SBRT), SABR is already used to treat certain lung and brain cancers. It is now being offered on the NHS to eligible men with low- and intermediate-risk localized prostate cancer.

Also read: Minimally Invasive Focal Therapy For Prostate Cancer Promises Fewer Side Effects Than Surgery Or Radiotherapy

Who Can Benefit?

Around 17,500 men in England are diagnosed with low- or intermediate-risk prostate cancer each year and could be eligible for SABR.

NHS modeling suggests that nearly one in five of these patients—around 3,500 men annually—may choose the treatment to help reduce the risk of their cancer spreading.

The treatment is expected to be available across all 48 NHS radiotherapy centers in England, with the first hospitals beginning to offer it from next week.

Could Reduce Waiting Times

The NHS estimates that introducing SABR for prostate cancer could free up around 50,000 treatment appointments each year.

By shortening treatment schedules and reducing the number of hospital visits, the rollout is expected to improve capacity across radiotherapy services while helping bring down waiting times for cancer patients.

However, SABR is not suitable for everyone with localized prostate cancer. Experts advise patients to discuss their treatment options with their specialist team, while ongoing research continues to evaluate the therapy in different patient groups.

What Is Prostate Cancer?

Read More: Over 40% Prostate Cancer Patients in India Diagnosed After Cancer Has Spread: ICMR study

The prostate is a small, walnut-shaped gland in men that produces seminal fluid, which nourishes and transports sperm. Prostate cancer develops when abnormal cells begin to grow uncontrollably in the gland.

Experts say not all prostate cancers are life-threatening. Many are slow-growing and may never affect a man's lifespan. In fact, such cancers are found in around one in three men over the age of 50. However, a smaller number of prostate cancers are aggressive, spread quickly, and require prompt treatment, making early detection and regular screening important.

Symptoms of Prostate Cancer

Early-stage prostate cancer may cause:

  • Blood in the urine or semen
  • Difficulty urinating
  • Erectile dysfunction

More advanced prostate cancer may lead to:

  • Decreased force of the urine stream
  • Bone pain
  • Unexplained weight loss.

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