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.

Squirrels could be natural hosts of the mpox virus (MPXV) -- that causes monkeypox disease -- according to a recent study by German researchers.

The team from the Helmholtz Institute for One Health (HIOH) identified the fire-footed rope squirrel (Funisciurus pyrropus) as a likely natural reservoir of the MPXV.

The study published in the journal Nature revealed that sooty mangabeys – a primate found in West Africa -- can contract mpox by eating infected squirrels. The disease may present mild lesions, but it can also cause more severe skin lesions or even be fatal.

"Identifying the animal sources of the virus and the exposure routes that lead to inter-species transmission are key steps towards understanding spillover mechanisms and developing effective prevention measures to mitigate the risk of transmission to humans," said Livia V. Patrono, one of the senior authors at HIOH.

Squirrels Suspected MPXV Hosts

While squirrels have long been suspected as potential reservoirs for MPXV, their role was confirmed after an investigation of an mpox outbreak among wild sooty mangabeys (Cercocebus atys) in Côte d'Ivoire.

During the outbreak, reported in early 2023, nearly one-third of the primates showed clinical signs of disease, and four infants died.

The team conducted viral genome sequencing and found that the infected monkeys carried a virus that was nearly identical to an MPXV strain identified in a fire-footed rope squirrel found dead 12 weeks earlier nearby.

Further, the team analyzed fecal samples from the mangabeys. A sample collected eight weeks before the outbreak's onset contained DNA from both the virus and the rope squirrel. This provided strong evidence of interspecies transmission at that moment.

Sooty mangabeys have been previously observed catching and eating fire-footed rope squirrels, which provide a direct route for the transmission of viruses.

Mpox Continues To Spread Globally

Although mpox is no longer a public health emergency, outbreaks of clade I and clade II strains of the mpox virus are continuing in many countries around the world, especially in Africa.

Last week, Madagascar announced the country's first death from mpox, a 3-year-old girl from the island nation’s eastern city of Toamasina.

The WHO has also confirmed that two cases of the recombinant strain – combining genomic elements of clades Ib and IIb of the monkeypox virus (MPXV) – have been identified to date: one in the United Kingdom and one in India.

Mpox is an infectious disease caused by the monkeypox virus (MPXV), part of the Orthopoxvirus genus, which also includes the virus that causes smallpox.

It spreads through close physical contact, including sexual contact, and in some cases through contaminated materials or respiratory droplets.

Symptoms typically include fever, swollen lymph nodes, rash, and/or lesions.

The global health body has also urged all countries to “remain alert to the possibility of MPXV genetic recombination.” It has also urged for continued epidemiological surveillance, sequencing, vaccination of at-risk groups, and infection prevention and control measures.

An international group of scientists has created an artificial intelligence tool that can estimate a woman’s likelihood of developing breast cancer within the next four years.

The AI tool, known as the BRAIx risk score, analyzes mammogram images to generate an individualized risk assessment and flag women who may face a higher chance of developing the disease.

It may not only show the current risk but also predict the future risk, enabling early detection and treatments for a better outcome.

According to the findings published in The Lancet Digital Health journal, nearly one in 10 women ranked in the top 2 percent of risk by the AI tool were diagnosed with breast cancer within four years. This was despite previously receiving a clear screening result.

“These risk scores enable future development of personalized screening pathways to transform population breast cancer screening and save lives,” said corresponding author Helen M. L. Frazer of the University of Melbourne.

Frazer noted that identifying women who appear cancer-free but carry very high risk -- comparable to those with inherited BRCA1 or BRCA2 mutations -- will unravel both hereditary and non-hereditary causes of breast cancer.

From one-size-fits-all screening to personalization

Breast cancer screening programs have significantly lowered mortality rates -- by roughly 40-50 percent among women aged 50 to 74. However, most screening systems still apply the same approach to all women, regardless of individual risk.

Traditional screening tools use genetics, breast density, and questionnaires to estimate breast cancer risk. On the other hand, new AI-based screening tools, such as BRAIx personalizes screening by gathering information already present in breast scan images to better identify who is at higher risk.

“Our results show that conventional mammographic density is a far weaker predictor of breast cancer risk than the BRAIx risk score, even for interval cancers,” the researchers said in the paper. Interval cancers are aggressive tumors diagnosed after a negative mammogram.

The BRAIx Tool

The BRAIx risk score was developed using mammograms from nearly 400,000 women. To prove its efficacy, the AI tool was tested on data from almost 96,000 women from Australia and then confirmed in an independent Swedish population of over 4,500 women.

The findings showed that:

• The BRAIx risk score estimated breast cancer risk more accurately than the traditional risk factors, such as breast density, country of birth, and even family history.

• For the top 2 percent of women with the highest BRAIx risk score, the probability of a cancer diagnosis within 4 years was 9.7 percent -- a risk level exceeding that typically seen in women with inherited BRCA1 or BRCA2 mutations.

The BRAIx risk score can:

• Make breast screening more personalised,
• Improve early cancer detection,
• Reduce false alarms,
• Save lives without increasing costs

Global Breast Cancer Burden

Breast cancer continues to be the most common cancer among women worldwide.

A recent study published in The Lancet Oncology journal predicted that the number of new cases of the deadly disease will reach more than 3.5 million globally in 2050 -- rising by a third from 2.3 million in 2023.

Annual deaths from the disease will also rise by 44 percent -- from around 764,000 to 1.4 million.

However, not smoking, getting sufficient physical activity, lowering red meat consumption, and having a healthy weight can help prevent over a quarter of healthy years lost to illness and premature death from breast cancer.

People who survived a COVID-19 infection can be at significant risk for kidney disease, acute kidney injury, and chronic kidney disease. compared to individuals who were not infected, according to a study.

The study, published online in the journal Communications Medicine, revealed that COVID patients have

• a 2.3-times higher risk of acute kidney injury
• a 1.4-times higher risk of chronic kidney disease
• a 4.7 times higher risk of kidney failure

“While we’re in the post-pandemic era, this shows that COVID-19 history is an important variable when considering the long-term impact of the infection on kidney function and disease,” said first author Yue Zhang, who was at Pennsylvania State University, US, while conducting the study. Zhang is currently a postdoctoral scholar at Johns Hopkins Bloomberg School of Public Health.

How Was The Study Conducted?

For the study, data on over 3 million working-age adults in the United States were analyzed.

The team compared the effect of influenza, another common viral infection that affects kidney health, and people with a history of COVID infection on kidney infections.

Using a machine learning model, the individuals were followed between 180 and 540 days for the emergence of new acute or sudden kidney disease.

The results showed that:

• Both COVID and the flu can worsen kidney health
• Flu caused a mild and temporary effect
• COVID increased the risk of acute kidney injury for a longer duration
• COVID survivors developed kidney disease within a few hours to a few days
• COVID patients had a longer-term chronic and end-stage kidney disease.

How COVID Worsens Kidneys Health

The Penn State researchers explained that kidney cells express high levels of the primary protein receptors that SARS-CoV-2 uses to enter and infect cells. Kidney cells also produce specialized enzymes that help viruses enter cells.

According to Kidney Health Australia, an acute COVID infection can impact the kidneys with fevers and respiratory symptoms, and/or worsening blood sugar control.

The US National Institutes of Health stated that renal dysfunction is an increasing clinical indicator of COVID propagation.

Citing several studies, the NIH said that the most common clinical manifestation is proteinuria -- found in more than half of the COVID patients. In addition, hematuria, elevated blood urea nitrogen, and elevated serum creatinine are other common features in Covid survivors with poor kidney health.

Nasr Ghahramani, Professor of Medicine at Penn State College of Medicine, stressed the need for COVID survivors, especially those with diabetes and high blood pressure, to take "more frequent and more prolonged monitoring of their kidney function" to enable early detection and better outcomes.