Stress is an unavoidable part of life, and while it often carries a negative connotation, it is actually a fundamental survival mechanism. When faced with a perceived threat, whether physical or emotional, the body instinctively reacts to protect itself. This automatic response is commonly known as the "fight, flight, or freeze" response. While it serves an essential function in dangerous situations, chronic activation of this response due to daily stressors can have significant consequences for mental and physical health.

The body’s response to stress is rooted in human evolution. When our ancestors encountered a predator, their nervous systems immediately prepared them to either confront the threat (fight), escape to safety (flight), or become still and unnoticed (freeze). While modern-day stressors may not include wild animals, our nervous system reacts similarly to job pressures, financial worries, or social conflicts.

According to the Cleveland Clinic, stress is the body's response to change, activating a physiological reaction that helps us adapt and protect ourselves. While short-term stress can be beneficial, prolonged exposure can lead to an overactive stress response, negatively impacting overall well-being.

The Three Stress Responses: Fight, Flight, and Freeze

1. Fight

The fight response prepares the body for direct action. When triggered, the nervous system releases adrenaline, increasing heart rate, blood pressure, and muscle tension. While this reaction once helped early humans fend off predators, today it manifests as irritability, frustration, or aggression.

For instance, the employee who has experienced too much workload may work extremely long hours just to succeed. In short term, the action may produce good results but mostly ends in burnout, anxiety, and physical illness, for example, tension headache or digestion problems.

2. Fight

The flight response triggers an intense need to remove oneself from a stressful situation. Just as our ancestors would flee from danger, modern individuals may avoid conflict, quit jobs impulsively, or detach from relationships when overwhelmed.

Flight mode is linked with restlessness and anxiety. Individuals may have a sense of needing to get up and go-pacing, changing environments constantly, or avoiding tasks that seem too overwhelming. Someone with a flight response might have the desire to change jobs constantly, relocate constantly, or become reclusive in order to avoid perceived dangers.

3. Freeze

The freeze response occurs when the nervous system perceives a threat as too overwhelming to fight or flee. Rather than taking action, individuals shut down, feeling numb, disconnected, or paralyzed by fear.

Unlike fight or flight, which involve heightened activation, freeze mode slows down physiological functions. A person experiencing freeze mode may feel physically unable to move, struggle to make decisions, or find themselves dissociating from their emotions. This can manifest in situations such as public speaking anxiety, where someone might "blank out" or feel stuck in the moment.

What Happens in the Body During A Stressful Event?

When faced with a stressor, the autonomic nervous system (ANS) activates, triggering physiological changes, including:

• Increased heart rate and breathing: The body pumps more oxygen to muscles and the brain in case action is needed.
• Muscle tension: The body prepares for movement, sometimes causing trembling or stiffness.
• Dilated pupils: Vision sharpens to detect potential threats.
• Dry mouth: Saliva production decreases as the body redirects energy to essential functions.
• Changes in skin tone: Blood flow is directed to vital organs, sometimes making the skin appear pale or flushed.

For those experiencing the freeze response, the body undergoes a different reaction, often reducing heart rate and causing physical immobility rather than heightened activation.

Strategies for Coping and Managing the Stress Response

While the stress response is necessary for survival, frequent activation due to daily stressors can take a toll on health. Recognizing your default response—whether fight, flight, or freeze—can help in developing effective coping mechanisms.

1. Moving to a Safe Space

If possible, changing your environment can help signal to your brain that the threat has passed. Stepping outside for fresh air, finding a quiet place, or distancing yourself from overwhelming stimuli can help regulate emotions.

2. Practicing Controlled Breathing

Deep, slow breathing can be used to counteract the stress response by engaging the parasympathetic nervous system, which promotes relaxation. Techniques such as diaphragmatic breathing or the 4-7-8 method (inhale for four seconds, hold for seven, exhale for eight) can be particularly effective in calming the body.

3. Engaging in Physical Activity

This helps release pent-up energy and aids in the endorphin cascade, natural boosters for our mood.

4. Seeking Social Support

Relieving oneself from stress can come in many ways, but sharing it with trusted friends, a family member, or a good therapist will sure give that psychological boost of hope. Social support is an especially effective way of cushioning people against the stressors that they are subjected to in chronic forms.

When to Seek Professional Help

While occasional stress is normal, chronic activation of the fight, flight, or freeze response can indicate underlying mental health concerns, such as anxiety disorders or post-traumatic stress disorder (PTSD). If stress is affecting daily life—leading to sleep disturbances, difficulty concentrating, or persistent feelings of fear—it may be time to consult a mental health professional.

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

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

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

“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 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

“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.

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

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 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

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

A Preventable Health Risk

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.