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Cold sores are a common and often frustrating skin issue. While they may look like harmless blisters, cold sores are actually caused by the herpes simplex virus (HSV).
Cold sores are caused by the herpes simplex virus (HSV), which comes in two types: HSV-1 and HSV-2.
HSV-1 is the primary cause of cold sores, usually appearing around the mouth.
HSV-2 generally causes genital herpes but can also lead to cold sores.
While the appearance of cold sores caused by both HSV-1 and HSV-2 can look similar, their locations tend to differ. However, it is possible for HSV-1 to cause sores on the genitals and for HSV-2 to appear on the mouth.
Cold sores are highly contagious and can spread easily. The virus can be passed on through:
Even when a cold sore isn’t visible, the virus can still be spread through close contact. This makes prevention and management key to reducing outbreaks and the risk of infecting others.
Once someone contracts HSV, it stays in the body for life. While the virus remains dormant most of the time, it can reactivate and cause new sores, especially during periods of:
Unfortunately, there’s no cure for the herpes virus, but the symptoms can be managed.
Cold sores don’t just appear out of nowhere. Before the sore is visible, you may notice a tingling or burning sensation around the lips or face, which can occur several days before the sore forms. This is the best time to begin treatment to shorten the outbreak.
When a cold sore does appear, it often looks like a red, raised blister filled with fluid. The blister can be painful to touch, and there may be more than one. Cold sores usually last around two weeks and are contagious until they crust over and heal.
Cold sores go through distinct stages as they develop and heal:
Certain factors can trigger the reactivation of HSV, leading to cold sores. These include:
There’s no cure for cold sores, but several treatments can ease the symptoms and help manage outbreaks.
Over-the-counter antiviral creams like docosanol (Abreva) or prescription ointments like penciclovir (Denavir) can help reduce the duration of an outbreak, especially if applied at the first sign of a cold sore.
Prescription antiviral medications like acyclovir, valacyclovir, and famciclovir can also help, particularly for people who have frequent or severe outbreaks. Your doctor may recommend taking these medications regularly to prevent future outbreaks.
There are also some home remedies that may provide relief, such as:
While cold sores and canker sores may seem similar, they are quite different:
Cold sores are caused by the herpes virus, appear around the mouth, and are contagious.
Canker sores are not contagious and appear as ulcers inside the mouth or throat.
To avoid spreading cold sores:
Cold sores can be a persistent issue, but with proper care and management, you can reduce the frequency of outbreaks and prevent spreading the virus to others.
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Worldwide, more than 57 million people live with dementia, experiencing symptoms such as short-term memory loss, difficulty finding words, confusion about time or place, trouble with complex tasks, and changes in mood or personality. Around 10 million new cases are diagnosed every year.
Recent studies suggest that the average lifetime risk of developing dementia after age 55 is about 42%.
A new study has found that maintaining healthy blood pressure, controlling blood sugar, and avoiding smoking during middle age could significantly reduce the risk of developing dementia.
People who maintained these three health measures between the ages of 48 and 68 lived, on average, nearly 13 additional years without dementia, according to the study published in the journal Neurology Open Access.
"Our findings argue that people need to actively avert these factors in midlife as a strategy for preserving brain health for more than a decade," said study senior investigator Josef Coresh, Professor in the Department of Population Health at NYU Langone.
"Discovering new ways to delay dementia is crucial with 42% of Americans at risk for developing the condition at any time after age 55," he added.
Researchers analyzed data from the Atherosclerosis Risk in Communities (ARIC) Study, an ongoing community-based study that began in 1986. It has tracked participants for decades, measuring midlife vascular risk factors and the development of dementia.
The analysis included 12,409 adults with an average age of 56, all of whom were free of dementia at the start of the study. Researchers assessed three key risk factors:
Researchers also examined how midlife cardiovascular risk factors affected dementia-free survival across different demographic groups.
Among participants with all three risk factors:
"Hopefully, these results will encourage people to stop smoking and watch their vascular health closely from age 48 on."
Dementia is an umbrella term for a significant decline in mental function that interferes with daily life. It commonly affects memory, thinking, and reasoning abilities and is caused by underlying conditions such as Alzheimer's disease or vascular dementia.
While there is currently no cure, the WHO says up to 45 per cent of dementia risk can be prevented or delayed by addressing modifiable risk factors such as tobacco and alcohol use, physical inactivity, social isolation, air pollution, and noncommunicable diseases (NCDs), including high blood pressure and diabetes.
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Through the first quarter of the twenty-first century, it has been clear that the global menace of infectious diseases has become very different in terms of their causal factors and predictability.
A 2022 review in Nature Reviews Microbiology by Princeton professors Rachel Baker and Jessica Metcalf aptly pointed out how climate change, urbanization, and wider travel and trade determine when, where, and how outbreaks of infections happen. Examples of such outbreaks are numerous globally, viz. SARS, H1N1, MERS, Ebola, Zika, and COVID-19 outbreaks. It has also been realized by biomedical scientists that more than half of all known pathogenic diseases have at some point been worsened by climate-change-related events.
As a result, research on climate-disease links has surged since the recent pandemic.
Evidence supporting this climate-disease relationship is also abundant in the Indian context. A major example is our experience with dengue infections, which are clearly losing their seasonal predictability. Contrary to its usual temporal link with the monsoon, India has encountered an unusually early transmission in 2026, with nearly 7,000 cases reported by end-February, as per the National Center for Vector-Borne Diseases Control data. The vector has also expanded its geographical distribution, for example into Himalayan towns such as Darjeeling over the past decade.
Meanwhile, the Integrated Disease Surveillance Program in India also reports bimodal waves of influenza transmission and infections with respiratory syncytial virus (RSV) surge during the monsoon. These provide evidence that overlapping and compressed disease seasons are becoming more common.
Warming temperatures and erratic rainfall alter mosquito breeding cycles and pathogen incubation periods, while floods can create sudden transmission spikes in a population. On the other hand, rapid urbanization increases overlap among human, animal, and vector habitats. India is expected to have an urban population of close to 600 million by 2031. This will further intensify livestock density, land-use change, and human-wildlife contact, raising the risk of zoonotic spillovers.
As is evident globally now, global travel and trade will carry the pathogens across borders way faster than health systems can respond. Thus, reactive outbreak responses, of testing, isolating, and reporting only after cases show a surge, are strategically too slow. However, genomic and wastewater surveillance offer scalable alternatives. For example, such efforts in India could detect SARS-CoV-2 variants in sewage much before case counts rose in a population.
Similar experience has been gathered in cities like Bengaluru, wherein wastewater monitoring could track influenza and RSV circulation independent of individual testing. Artificial intelligence and machine learning models further add to the forecasting capacity. Modelling climate, land-use, and animal-movement data can flag likely zoonotic spillover risks well before an outbreak begins.
India's national zoonotic disease prioritization exercise and state-level One Health pilot studies in Gujarat and Rajasthan show that human, veterinary, and environmental data must be integrated. Such interdisciplinary cohort research, tracking populations across seasons and geolocations, can achieve usable forecasts integrating discrete data. Thus, building such predictive, One Health-oriented research and surveillance infrastructure will be imperative for India to achieve optimal pandemic preparedness.
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It has been long suspected that Western diets could contribute to the risk of colorectal cancer. The theory may finally have a clearer scientific explanation.
A new study suggests that gut bacteria can convert compounds produced by high-fat, low-fibre diets into cancer-causing chemicals. The research sheds light on how unhealthy eating habits may lead to cancerous tumour growth in colon in the long term.
Published in the journal Gut, the research was led by Dr. Annika Osswald (first author) and Dr. Soeren Ocvirk (corresponding author), along with a large team of international scientists.
The collaboration included researchers from Technical University of Munich (TUM), Germany, German Institute of Human Nutrition (DIfE), RWTH Aachen University, Freie Universität Berlin, University Hospital of Regensburg, and other institutions.
Researchers found that a western-style diet, which is commonly high in red and processed meat, saturated fats, refined carbohydrates and ultra-processed foods, significantly changes the composition of the gut microbiome.
These altered bacteria then modify bile acids in ways that promote inflammation and create an environment that accommodates the development of colorectal cancer tumours.
According to the researchers, diet alone is not the only factor. The trillions of microbes living in the intestine determine how food is processed, producing metabolites that can either protect the gut or damage it.
The study found that specific bacterial groups transformed bile acids into compounds that stimulated tumour growth in the colon.
This provides one of the strongestt explanations yet for why western dietary patterns have consistently been associated with higher risk of colorectal cancer.
"Our findings highlight the critical interaction between diet, gut microbes and cancer biology," the researchers noted, adding that targeting the microbiome could become a future strategy for preventing colorectal cancer.
Also read: Why English Actor Peter Duncan Is Advocating For Focal Therapy After His Prostate Cancer Treatment?
A western diet typically includes:
Previous research has repeatedly linked this eating pattern with obesity, diabetes, heart disease and colorectal cancer, but scientists have long found it challenging to explain the exact cause until now.
The human gut is home to trillions of bacteria that help digest food, regulate immunity and produce beneficial compounds like fatty acids.
A fibre-rich diet supports good bacteria that reduce inflammation, whereas diets high in fat and processed foods can cause microbial imbalance.
The new findings suggest this imbalance changes how bile acids are metabolised, increasing the production of molecules capable of damaging the colon and supporting cancer growth in the long run.
Also read: WHO Cancer Agency Flags 3 Common Medicines As Carcinogenic: What It Means For Millions Of Patients
Earlier research has linked harmful gut bacteria, including toxin-producing E. coli, with DNA damage that may begin early in life and contribute to the rise of colorectal cancer among younger people.
However, the latest findings do not prove diet alone causes cancer. Genetics, obesity, physical inactivity, sedentary life, smoking and alcohol consumption also influence risk.
However, they say maintaining a fibre-rich diet with fruits, vegetables, legumes and whole grains may help preserve a healthier gut microbiome and lower long-term colorectal cancer risk.
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