The world that we live in is filled with sounds, some are comforting and some could be jarring too. But what if the constant noise surrounding us is doing us more harm than we realize? There has been immense research that shows that noise is not just a nuisance, but a silent killer and affects our health in ways we do not even know. There are associations of sound causing heart attacks, type 2 diabetes, and dementia.

How Does Your Body Respond To Noise?

Noise is seen as an annoyance, but it effects can go beyond what we imagine. When we hear a sound, it travels through the ear to the brain. This is where it gets processed by the amygdala. It is a region that is responsible for emotional responses. This also triggers a stress response- our heart rate increases, our blood pressure rises, and stress hormones like cortisol flood our system.

This response is also designed to help us react to immediate threats. Especially, if we hear the sound of a predator approaching. However, when we are exposed to constant noise, this response is triggered repeatedly and could compel us to live in a long-term anxious state.

Hidden Health Risks

Many studies including Harvard Health and theAmerican College of Cardiology have found associations of noise with health problems including putting a person at a higher risk of cardiovascular diseases such as heart strokes, attacks, and high blood pressure. The constant activation of the stress response can take a toll on the body, increasing inflammation and making it harder for the heart and circulatory system to function properly. Over time, this can lead to serious health conditions like heart disease and diabetes.

Even more troubling, research suggests that noise pollution may contribute to mental health issues. Studies have found a strong connection between exposure to noise and disturbed sleep, which in turn can cause anxiety, depression, and cognitive decline. The World Health Organization estimates that noise contributes to around 12,000 premature deaths annually across Europe alone. This invisible threat, however, is often overlooked because the effects are gradual and cumulative.

Noise and Sleep: A Silent Disturbance

One of the most insidious aspects of noise pollution is its impact on sleep. Even when we are asleep, our bodies are not fully immune to the effects of sound. Our ears never fully “turn off,” meaning that even faint noises can disrupt our sleep cycle. Research has shown that people who live in noisy environments—whether near busy roads, airports, or urban centers—often experience fragmented sleep, leading to fatigue and a weakened immune system. Over time, this chronic lack of restful sleep can lead to significant health problems, including an increased risk of developing cognitive disorders such as dementia.

The Urbanization Problem

As cities continue to grow, noise pollution is becoming more widespread. Traffic noise, in particular, is one of the most common and harmful sources. The rise of urbanization means more cars, buses, and trains, all of which contribute to an ever-increasing din. This urban soundscape is often relentless, with little respite for those living within it. In densely populated cities, people are exposed to high decibel levels, which can exceed safe thresholds for heart health. In many cases, the sheer volume of sound is not just unpleasant; it’s dangerous.

What Can We Do About It?

The solution is not as simple as reducing noise in our immediate surroundings, though efforts to reduce traffic noise and limit industrial sounds are essential. Some cities have taken steps to create quieter spaces by converting busy roads into pedestrian zones or installing noise barriers. These measures have shown to have a positive impact on public health, with research suggesting that even small reductions in noise can prevent premature deaths and improve overall well-being.

Someone who is dying may start to their loved ones who passed away years ago. This could be unsettling and confusing for families and relatives who may assume that the person is just hallucinating or undergoing a deeper neurological issue.

But hospice physician Dr Christopher Kerr says such experiences are a known phenomenon called end-of-life dreams and visions (ELDVs). Kerr, chief medical officer of Hospice Buffalo, has spent decades studying these experiences in dying patients extensively.

Appearing on The Oprah Podcast, he told Oprah Winfrey that many patients near death describe seeing deceased relatives or people who cared for them during their lives. The experiences can feel completely real to them.

Why Do People Near Death See Deceased Loved Ones?

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One of the possibilities is that the brain experiences significant changes as the body starts to shut down.

Alterations in sleep, consciousness, metabolism, oxygen levels, medications, and brain chemistry can all affect perception during the final stages of life.

Dr. Rakesh Lalla, Additional Director - Neurology, Fortis Hospital, Mumbai, told HealthandMe, " These visions could be explained by the alterations that occur within the brain as the body starts to close down. Due to oxygen deprivation and altered brain activity, the brain would process memories, feelings, and stimuli differently. The areas responsible for memory processing and vision could become stimulated or disrupted, which could result in some vivid visions or experiences."

The expert also said that these visions do not mean that the person has a neurological or psychiatric issue.

Dr. Lalla said, "They do not necessarily mean that the person is confused or suffering from a psychiatric condition. In many cases, they are brief, peaceful, and emotionally meaningful to the individual. We still do not fully understand why particular people or memories appear."

The neurologist also advised families to stay supportive and calm during such situations.

He added, "The brain’s complex relationship between memory, emotion and perception is likely to play an important role. For families, the key is to remain calm, listen without dismissing the experience, and provide reassurance and comfort."

Also read: Global Life Expectancy Returns To Pre-Pandemic Levels, But NCDs Resulted In 8 Out 10 Deaths: WHO

Hallucinations Or Part Of The Dying Process?

Experts who have been studying ELDVs have also found that these experiences have some distinctive patterns that do not resemble random hallucinations.

In a 2014 longitudinal study led by Kerr, most of the 59 hospice patients who completed the study reported at least one dream or vision. Almost half occurred during sleep, and nearly all patients said the experiences felt real. The most common involved deceased friends or relatives or other loved ones. In fact, comforting visions of deceased people became more common as patients moved closer to death.

A 2026 systematic review of 13 studies similarly found that ELDVs occurred in at least one in five dying adults.

The National Institute on Aging also states that dying people may appear to see or talk to someone who is not present and may report dreams involving deceased relatives or friends. Such experiences are often comforting, and caregivers are generally advised not to immediately correct or challenge the person.

Seeing Loved Ones Could Be A Comforting End

Kerr said that patients seeing deceased loved ones in their visions appeared calmer afterward. His research suggests that these experiences may carry deep emotional meaning for patients.

“Very little is said between the person in the dream and the dreamer, but everything seems to be understood,” Kerr told Oprah.

Scientists still cannot say exactly what produces these experiences or whether they represent anything beyond changes occurring in the dying brain.

India accounts for one-fifth of global deaths due to cardiovascular diseases (CVDs) or complications related to the heart and blood vessels. Moreover, women are more vulnerable to these complications. Recent data show that women (14%) have a higher prevalence of CVD than men (12%), making preventive care very important for all.

When Should A Heart Check-up Be Done?

The human heart works constantly and efficiently and can compensate for metabolic stress and narrowing of blood vessels without showing any obvious symptoms. Hence, a heart health evaluation should ideally take place when the person is feeling completely well, long before any warning signs appear.

While acute symptoms, such as chest pressure or tightness, unexplained breathlessness, fainting, or unusual fatigue on effort, demand immediate attention, true heart protection occurs through early and planned tests. While heart check-ups are routinely recommended starting at age 40, screening should ideally begin earlier, around ages 30 to 35, especially if risk factors are present.

Starting check-ups at age 30 is important because certain congenital and structural heart conditions remain completely silent for years, and early screening ensures timely, targeted treatment when it is most effective.

Regular screening helps detect and rule out underlying issues early, including congenital heart defects (commonly known as holes in the heart) and conditions such as Atrial Septal Defect (ASD), Ventricular Septal Defect (VSD), or Patent Ductus Arteriosus (PDA). Structural and muscle diseases, on the other hand, include valve disorders, heart muscle weakness, or abnormal thickening of the heart walls (e.g., Hypertrophic Obstructive Cardiomyopathy (HOCM)).

Key Risk Factors

In addition to age, patients should seek a heart check-up sooner if they have any of the following risk factors:

• Strong family history of premature heart disease in immediate relatives.
• History of active or past smoking and tobacco use.
• Metabolic conditions such as diabetes, hypertension, or elevated blood cholesterol.

Excess body weight, especially central or abdominal obesity. Excess body weight damages the kidneys, leads to fat deposits in the liver and increases the risk of developing diabetes, and ultimately increases the strain on the heart and blood vessels (cardiovascular system). These interconnected conditions are known as Cardiovascular-Kidney-Metabolic (CKM) syndrome and include heart disease, kidney disease, diabetes, stetotic (fatty) liver disease, and obesity.

Effective weight and metabolic management, through modern options such as oral or injectable GLP1 therapies, can improve long-term heart health.

Tailoring care

A heart check-up can involve several tests, from blood tests to invasive or non-invasive ones (with/without needles, catheters, or probes entering the body). The most common blood tests include fasting and post-prandial or after-meal blood sugar (FBG/PPBG), HbA1c (glycated haemoglobin), lipid and thyroid profile, and kidney function tests. Non-invasive cardiac tests include electrocardiogram (ECG), 2D echocardiogram, and ultrasound. However, not everyone needs all of them.

Diagnostic tests should be customized based on the person’s age, symptoms, and individual risk score. Hence, skip the urge to self-order commercial diagnostic packages online. Instead, take the most important step towards protecting your heart by talking to your doctor. A personalized assessment can help determine which tests, if any, are appropriate for you, so that you can focus on the right steps to keep your heart healthy.

Gut chemicals may play a role in influencing the likelihood of someone developing Alzheimer's disease. A new study has a chemical produced by certain gut bacteria in focus that may affect Alzheimer’s disease risk, cognitive decline, and other changes related to the disease.

Published in Nature Communications, the study focused on imidazole propionate (ImP), a metabolite produced by some gut bacteria when they break down the amino acid histidine.

Researchers found that people with higher levels of ImP in their blood had lower cognitive scores and higher levels of biomarkers that indicate the likelihood of Alzheimer’s disease and neurodegeneration.

How Was The Study Conducted?

Also read: Global Life Expectancy Returns To Pre-Pandemic Levels, But NCDs Resulted In 8 Out 10 Deaths: WHO

The researchers studied health data from 1,196 adults who were cognitively unimpaired, with an average age of about 61 years. Higher blood levels of ImP were associated with poorer cognitive performance and faster age-related decline.

Higher ImP was also linked to increased levels of p-tau217, a key biomarker in Alzheimer’s pathology, and neurofilament light chain, a marker of nerve-cell damage.

The finding builds on earlier work from the University of Wisconsin-Madison team showing differences in gut microbes between people with Alzheimer’s and those without the disease.

“Since then, we've been trying to figure out how this difference in the gut perhaps leads to changes in the brain,” said Barbara Bendlin, professor of medicine at the University of Wisconsin-Madison.

But ImP itself may be more relevant than simply having a particular type of gut bacteria.

“ImP-producing bacteria are present in a large fraction of people, but they're not very abundant in most people,” said Federico Rey, professor of bacteriology at the University of Wisconsin-Madison. “But something we have learned over the years is that a microbe doesn't have to be abundant to have an impact on the host.”

Also read: Could This Popular Joint Supplement Turn Mild Cognitive Impairment Into Dementia? New Study Finds Link

Could Changing Your Diet Prevent Dementia Risk?

The researchers also found genetic evidence that linked higher ImP levels with an increased risk of Alzheimer’s. In experiments on mice, long-term exposure to ImP increased amyloid-beta plaques and signs of brain inflammation.

Laboratory experiments further suggested that ImP could affect the blood-brain barrier and promote tau hyperphosphorylation, a process involved in nerve damage that occurs in Alzheimer’s.

Researchers also caution against making changes to diet to alter gut bacteria. They say ImP is produced when bacteria metabolise histidine, an amino acid that the body needs and that is found in many protein-rich foods.

“Generally improving your diet would probably help,” Bendlin said. “But it's not as easy as saying, 'Stop eating eggs' or 'Don't eat so much red meat.' Because you need histidine, and it's all over the place.”

Instead, the researchers are looking at whether ImP itself could eventually be targeted.

“It could be just like cholesterol, where people with elevated cholesterol take a drug, a statin, that reduces their risk for heart disease,” Bendlin said. “If we can find an inhibitor that can help decrease the levels of ImP in the blood, that could hopefully reduce the risk of Alzheimer's and the speed of cognitive decline for a significant number of people.”

Researchers also say that the findings do not show that ImP causes Alzheimer’s in humans, nor do they suggest that probiotics or dietary changes can prevent dementia.

But they strengthen growing evidence that suggest chemicals produced by gut microbes may affect brain health years before symptoms surface.