Why Do Mosquitoes Bite Some People More Than The Others?

Updated Jul 26, 2024 | 01:25 PM IST

SummaryMosquitoes love biting some people more than others! They are attracted to your breath (CO2), sweat, dark colours, and even your body heat. Here is what you need to know.
Mosquitoes Bite Some People (Credit-Freepik)

Mosquitoes Bite Some People (Credit-Freepik)

Mosquitoes are a big part of the ecosystem, but often are a nuisance as they bite and feed off of us. Their bites cause itchy red bumps and spread infections and allergies in our bodies. But have you ever wondered why they bite certain people more than others? While some people are plagued by mosquito bites, others barely notice them. Here are some interesting facts about mosquitoes that you must know about!

1. Carbon Dioxide:

Mosquitoes are attracted to a certain smell that emits from the human body that is present in the human skin and sweat, mosquitoes can sense the carbon dioxide or CO2 we breathe out. The more active you are, the more CO2 you emit and the more mosquitoes will be attracted to you. Researchers are still investigating the cause of the variation of body odour that brings them to you, possibly genetics or certain bacteria. The unique combination of sweat and skin bacteria creates a scent that mosquitoes find irresistible. Some chemicals in sweat, like lactic acid and ammonia, are especially attractive to them.

2. Colours

While the reason isn't fully understood, mosquitoes seem to be drawn to dark colours like black more than lighter ones. So, ditch the dark outfit next time you're in mosquito territory. It has been noted that mosquitoes are more likely to leave lighter colours alone.

3. Heat and Vapour

Mosquitoes can detect your body's heat and water vapour, acting like a beacon guiding them right to you. So next time you're feeling sweaty, be aware you might be attracting a lot of mosquitoes. If you are working out or doing something that is making you sweat and your body heat rise, the mosquitoes nearby will be instantly attracted to you. Even mosquitoes are careful about who they pick as a host, some studies even suggest that they like a certain body temperature to feed off of.

An interesting fact about mosquitoes is that they can learn to like a host. They have their own preferences and if they meet a certain person who fits their criteria they might be the next host they move onto. In an older study, it showed that 20 per cent of people with mosquito-borne diseases accounted for 80 per cent of diseases transmitted in the population. They suggest that they only bite a certain set of people within the population.

4. Other factors:

Studies suggest mosquitoes might learn to prefer certain people based on things like what you've been drinking. In a 2002 study, there could be many reasons they like alcohol to making your body temperature high etc. Even pregnant women seem to be extra attractive to them due to higher body temperature and CO2 output.

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AI-powered Screening Tool To Boost Glaucoma care: The Lancet

Updated Mar 13, 2026 | 09:00 PM IST

Summary​Glaucoma is a chronic disease that affects an estimated 80 million individuals globally. By the year 2040, it is estimated that there will be 22 million individuals worldwide who are blind from glaucoma.
AI-powered Screening Tool To Boost Glaucoma care: The Lancet

Credit: Canva

An international team of researchers has developed an artificial intelligence (AI)-based tool that can significantly improve care for glaucoma -- a leading cause of irreversible blindness worldwide, according to a study published in The Lancet Primary Care journal today.

Researchers led by those from the University of Lisbon in Portugal found that the AI-based screening tool halved the number of unnecessary referrals for glaucoma.

The study, released during the Glaucoma Awareness Week, also showed an accuracy level at par with human eye doctors.

"The high accuracy at excluding people without glaucoma is especially important, as false alarms can lead to unnecessary hospital visits, patient anxiety, and added strain on healthcare services," the researchers said.

According to the researchers, AI-based screening could:

  • support earlier detection,
  • reduce unnecessary specialist referrals,
  • prevent avoidable vision loss,
  • can be integrated into routine primary care in a cost-effective way

Key Findings

The study was carried out at a single screening center in Lisbon, Portugal, in 2023.

The experts screened 671 adults aged 55-65 for glaucoma via the AI tool, analyzing images of the eyes. The images were then independently graded by six glaucoma experts.

The AI-tool:

  • referred 66 people (9.8 percent) vs 118 referrals (18.0 percent) by the eye doctors,
  • diagnosed glaucoma in 40 participants (6.4 percent).
  • It correctly identified 78 percent of people who truly had glaucoma, vs 75 percent identified by the eye doctors
  • Correctly ruled out the disease in 95 percent of people, vs 91 percent by eye doctors

While modelling studies suggest that screening could substantially reduce glaucoma-related visual impairment and blindness, barriers include the need for specialised diagnostic equipment and trained personnel, particularly in low- and middle-income countries, and the intrinsically low positive predictive value of screening tests.

In such a scenario, the new study showed that "AI may provide a more viable option than population-wide screening", which may seem impractical.

What Is Glaucoma?

Glaucoma is a chronic disease that affects an estimated 80 million individuals globally, according to the World Glaucoma Association.

It is a progressive, degenerative disorder of the optic nerve that produces characteristic visual field damage.

The disease stems from a long asymptomatic phase, resulting in substantial underdiagnosis and delayed treatment.

Even in high-income countries, up to 50 percent of individuals with glaucoma remain undiagnosed, frequently presenting moderate to advanced disease at first detection.

By the year 2040, it is estimated that there will be 22 million individuals worldwide who are blind from glaucoma.

When to see a doctor for glaucoma:

  • Vision suddenly gets blurry
  • Severe eye pain
  • Headache
  • Nausea
  • Vomiting
  • Rainbow-colored rings or halos around lights

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Sleep Loss In Early Life May Increase Autism Risk, Researchers Say

Updated Mar 13, 2026 | 06:43 PM IST

SummaryScientists found that sleep loss during critical stages of growth can influence how brain cells connect and may interact with genetic factors linked to neurodevelopmental conditions such as autism.
Sleep Loss In Early Life May Increase Autism Risk, Researchers Say

Credits: Canva

In adults, long periods of sleep deprivation has been linked to problems such as weakened immunity, weight gain, depression, and an increased risk of dementia. However, scientists are now paying closer attention to how sleep affects the brain much earlier in life.

However, a new University of North Carolina School of Medicine study suggests that disrupted sleep during early childhood may interfere with key stages of brain development and asl well as increase the risk of developing autism.

Why Sleep Matters For The Developing Brain

From the moment babies are born, their brains are rapidly developing. During this stage, neurons form connections with one another through structures called synapses. These connections allow brain cells to communicate and are essential for learning, attention, working memory, and long term memory.

Sleep plays a crucial role in helping these synapses form and strengthen. During sleep, the brain organizes and stabilizes these neural connections, shaping the foundation for future brain function. If sleep is repeatedly disrupted during this delicate stage of development, the process may be affected.

Frequent waking or sleep disturbances could interfere with how these neural connections are formed, potentially influencing behavior and cognitive abilities later in life.

The Link Between Sleep And Autism

Sean Gay, a graduate student in the laboratory of Graham Diering, PhD, assistant professor in the Department of Cell Biology and Physiology at the UNC School of Medicine and lead author said that more research was needed to determine the exact link between sleep and the development of autism.

“The unique effects of sleep loss during development are largely unexplored,” Diering said. “Our data show that babies and children are more vulnerable to the negative effects of sleep disruption. We also found that sleep loss during this crucial period of time can negatively interact with underlying genetic risk for autism spectrum disorder.”

Sleep problems are already known to be common in people with autism. In fact, sleep disruption has been reported in more than 80 percent of individuals with autism spectrum disorder. However, researchers have long debated whether these sleep issues are a cause of the disorder or a consequence of it. Understanding how sleep interacts with brain development could help scientists detect autism earlier and potentially develop new treatment strategies.

Studying Sleep Disruption In Early Life

In earlier work conducted in 2022, researchers examined how sleep disruption during early life might interact with genetic factors linked to autism. Using mouse models, they disrupted sleep during the third week of life, a developmental stage roughly comparable to ages one to two in humans.

The study found that sleep disruption during this period produced long lasting behavioral changes. Male mice that were genetically vulnerable to autism showed deficits in social behavior later in life. These results suggested that sleep disruption during critical stages of development may interact with genetic risk factors in ways that shape long term behavior.

Younger Brains Respond Differently To Sleep Loss

To investigate further, researchers studied how developing and adult mice respond differently to sleep deprivation.

Using specially designed housing systems equipped with sensitive sensors, scientists tracked the animals’ breathing and movement. This allowed them to determine when the mice were awake and when they were asleep.

The researchers observed that adult mice were able to compensate for lost sleep. After experiencing sleep deprivation, the adults increased their sleep later during their normal active period. This process, known as sleep rebound, allowed them to recover some of the lost rest.

Younger mice behaved very differently. They showed no sleep rebound at all, meaning they did not compensate for the sleep they had lost. This finding suggests that younger brains may be far more vulnerable to the effects of sleep disruption.

The consequences were also visible in cognitive performance. Sleep deprived young mice performed poorly on learning and memory tasks, while adult mice were significantly more resilient after losing sleep.

Changes At The Level Of Brain Synapses

The researchers also examined what was happening inside the brain at the molecular level. Synapses are the points where neurons communicate, and they play a central role in memory formation and learning. Because sleep is closely linked to how synapses function, the team analyzed how sleep deprivation affects these structures. Using advanced protein analysis techniques, researchers mapped changes in the proteins that regulate synapses.

The results showed that sleep deprivation in young mice significantly altered the formation of synapses. These changes were not seen in adult mice. “This now provides one of the largest and most comprehensive datasets to examine the molecular effects of sleep loss across the lifespan,” Diering said.

Potential Future Treatments

The research team hopes their findings may eventually help guide the development of new treatments for autism and other neurodevelopmental conditions. One goal is to create sleep based therapies for children that work differently from traditional sleep medications. Instead of acting as sedatives, these treatments would target the biological mechanisms that regulate synapses and sleep function.

“Development is not something that one can go back and do again,” Diering said. “Sleep is important for the entire life and especially during development. Understanding what we know now will place greater emphasis on understanding sleep issues in ASD and could lead to an important therapeutic avenue to treat ASD and other developmental conditions.”

The findings highlight an important message for parents and caregivers. During early childhood, healthy sleep patterns may play a critical role in shaping the brain for years to come.

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Recreational Drugs Increase Brain Stroke Risk In Young Adults, Study Finds

Updated Mar 13, 2026 | 06:22 PM IST

SummaryThis article explores new research that raises questions about how certain recreational drugs may affect stroke risk. It looks at what scientists have discovered so far and why the findings are drawing attention to an often overlooked health concern.
Popular Recreational Drugs Increase Stroke Risk In Young Adults, Research Says

Credits: Canva

Using amphetamines, cocaine and cannabis can significantly increase your risk of having a brain stroke particularly among younger adults, according to a new University of Cambridge analysis

The findings highlight how recreational drug use may contribute to a preventable health risk, especially among people under the age of 55.

Megan Ritson, a stroke genetics researcher at the University of Cambridge and lead author said the results provide strong evidence linking certain drugs to stroke risk.

“These findings provide compelling evidence that drugs like cocaine, amphetamines, and cannabis are causal risk factors for stroke,” Ritson noted.

A stroke occurs when blood flow to part of the brain is interrupted. This can happen when a blood vessel becomes blocked by a clot, known as an ischemic stroke, or when a blood vessel bursts and causes bleeding in the brain, known as a hemorrhagic stroke. Both types can lead to serious brain damage and can be life threatening.

Amphetamines Associated With The Highest Risk

Among the substances examined, amphetamines were linked to the largest increase in stroke risk. Amphetamines are powerful stimulants that affect the central nervous system and can significantly increase heart rate and blood pressure. In illegal forms, they are often sold under street names such as meth or ice.

When researchers combined data from eight previous studies, they found that recreational amphetamine use was associated with more than double the risk of stroke across all adult age groups. For individuals under the age of 55, the increase was even greater. In this group, amphetamine use was linked to nearly triple the risk of stroke compared with people who do not use the drug.

Across all age groups, the analysis found that amphetamine use increased the risk of ischemic stroke by 137 percent and hemorrhagic stroke by 183 percent. These figures reflect relative risk, meaning the probability of stroke is higher among users compared with non users.

Cocaine Shows A Similar Pattern

The researchers also found a strong association between cocaine use and stroke. Cocaine is another central nervous system stimulant that can raise blood pressure and constrict blood vessels. These effects may increase strain on the brain’s blood vessels and raise the likelihood of both clot formation and vessel rupture.

The analysis showed that cocaine use nearly doubled the risk of stroke of any kind and more than doubled the risk of hemorrhagic stroke. Additional genetic investigations were conducted alongside the main analysis to better understand whether the relationship might be causal rather than simply linked to other lifestyle factors.

Eric Harshfield, a genetic epidemiologist at the University of Cambridge, said the findings suggest the drugs themselves may play a direct role. “Our analysis suggests that it is these drugs themselves that increase the risk of stroke, not just other lifestyle factors among users,” Harshfield said.

Cannabis Linked To Smaller But Significant Risk

Compared with amphetamines and cocaine, the association between cannabis use and stroke was smaller but still statistically significant. Researchers reviewed 19 previous studies investigating cannabis use and stroke outcomes. The analysis found that recreational cannabis use was associated with a 16 percent increase in the risk of any stroke and a 39 percent increase in the risk of ischemic stroke.

Among people under the age of 55, cannabis use was linked to a 14 percent increase in stroke risk. Although the increase is lower than that associated with stimulant drugs, researchers say it remains important because cannabis is widely used.

Opioids Showed No Clear Association

The analysis did not find evidence linking opioid use to an increased risk of stroke. However, researchers caution that stroke risk can be influenced by many factors. These include how long a person has used a drug, how much they use, their overall health, diet, genetics, and socioeconomic environment. Heavy alcohol use is also known to increase the risk of stroke and may worsen the effects of other substances.

A Preventable Health Risk

Experts say the findings highlight the need for greater awareness about how recreational drugs can affect long term health, particularly among younger people who may not associate stroke with their age group. “Illicit drug use is a preventable stroke risk,” Ritson explained. “I don’t know if young people are aware how high the risk is.”

The researchers also note that many of the studies included in the analysis relied on participants reporting their own drug use. Because of this, other lifestyle factors could potentially influence the results. Further research will be needed to better understand the biological mechanisms involved and how different patterns of drug use may affect stroke risk. Still, scientists say the evidence now available provides an important foundation for future public health strategies.

“These findings give us stronger evidence to guide future research and public health strategies,” Ritson said.

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