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).

What Causes Cold Sores?

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.

How Do Cold Sores Spread?

Cold sores are highly contagious and can spread easily. The virus can be passed on through:

• Kissing or skin contact
• Sharing food, drinks, or cosmetics (such as lip balm)
• Oral sex, which can spread both cold sores and genital herpes

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:

• Stress
• Illness
• A weakened immune system

Unfortunately, there’s no cure for the herpes virus, but the symptoms can be managed.

Symptoms of Cold Sores

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.

The Five Stages of a Cold Sore

Cold sores go through distinct stages as they develop and heal:

• Tingling and itching: You may feel these symptoms about 24 hours before the blister appears.
• Blisters: Small, fluid-filled blisters form, typically around the mouth.
• Bursting: The blisters burst and form painful sores.
• Scabbing: The sores dry out, scab over, and may itch or crack.
• Healing: The scab falls off, and the cold sore heals.

Risk Factors for Cold Sores

Certain factors can trigger the reactivation of HSV, leading to cold sores. These include:

• Infection, fever, or cold
• Sun exposure
• Stress
• Menstruation
• Dental work or injury
• Weakened immune system due to conditions like HIV/AIDS, eczema, or chemotherapy

Managing and Treating Cold Sores

There’s no cure for cold sores, but several treatments can ease the symptoms and help manage outbreaks.

Topical Ointments and Creams

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.

Oral Medications

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.

Home Remedies

There are also some home remedies that may provide relief, such as:

• Applying ice or a cold washcloth to the sore
• Using aloe vera gel or lemon balm lip balms
• Applying petroleum jelly to ease discomfort

Canker Sores vs. Cold Sores: What's the Difference?

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.

Preventing the Spread of Cold Sores

To avoid spreading cold sores:

• Wash your hands frequently
• Avoid close contact with others during an outbreak
• Don’t share food, drinks, or personal items like lip balm

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.

Living in cities could mean your home may be located near a busy road, railway line or airport. It also means your comfort and sleep may get interrupted from time to time due to excessive noise. After living at such places for a long time, the traffic sounds may turn into white noise for you but it does not mean that you are completely safe.

A recent study says that constant exposure to transportation noise could increase your risk of cardiovascular disease, even if you sleep for seven to nine hours every night.

The research, presented at the American Heart Association's (AHA) Scientific Sessions 2026, found that adults who were exposed to higher levels of transportation noise were more likely to face cardiovascular risk factors like high cholesterol, hypertension and diabetes.

The study is based on health records of 108,051 adults, with an average age of 57 years. They also used US government data to estimate average daily transportation noise levels around the homes of participants. About one-third of participants were exposed to noise levels exceeding 50 decibels.

Transportation Noise & Heart Disease Risk

Also read: Bowel, Pancreatic & Liver: NHS Trial Offers New Blood Test To 20,000 Patients That Could Detect 13 Cancers

The study found that exposure to transportation noise above 50 decibels could lead to an 8% to 10% increase in the development of major cardiovascular risk factors. The researchers examined average 24-hour transportation noise levels above 45 to 50 decibels. These estimates included noise from road traffic, trains and aircraft.

Dr Joseph Nguyen, an internal medicine resident at Massachusetts General Hospital, emphasised that the measurements represented daily averages rather than peak noise levels. "These levels are similar to moderate rainfall or typing on a keyboard," he explained.

He added that noise levels can rise considerably during specific events. Subway stations, for example, may reach more than 100 decibels when trains arrive or depart.

In terms of individual risk factors, the strongest link was observed with high cholesterol, followed by high blood pressure and diabetes.

One of the findings that stood out in the study is that the cardiovascular risk due to transportation noise was the same among those with healthy as well as unhealthy sleep schedules.

For this study, unhealthy sleep was defined as having a diagnosed sleep disorder or regularly sleeping fewer than seven hours or more than nine hours per night.

"The key finding of our study is that the relationship between noise exposure and cardiovascular disease events, and the number of cardiovascular risk factors developed, was similar among people with and without unhealthy sleep, suggesting that healthy sleep is not protective against adverse heart impacts of noise exposure," said Dr Nguyen.

"We expected that disordered sleep would influence the relationship between noise exposure and heart disease. It was surprising to find that sleep health appeared to play no role," he added.

Also read: NCCN Issues First-Ever Guidelines For Cancer Caregivers

How Could Noise Exposure Affect Heart Health?

Experts believe that long-term exposure to transportation noise may activate the body's stress response, which could affect cardiovascular health over time.

Even when people do not wake up or feel disturbed by noise, their bodies may still unconsciously respond to these environmental sounds.

This could result in changes in stress hormones, blood pressure and other processes. Repeated exposure may contribute to cardiovascular strain over time.

How To Reduce Exposure To Traffic Noise?

Researchers suggested several ways people living in noisy neighbourhoods could reduce exposure inside their homes:

• Install thicker windows, doors and walls to improve sound insulation.
• Place bedrooms in the quietest areas of the home.
• Plant dense trees and vegetation around the property.
• Consider using earplugs while sleeping.

Dr Nguyen said the findings highlight the importance of reducing environmental noise through better urban planning and infrastructure for protecting long-term cardiovascular health.

Women's bodies have long been understudied, and even a simple touch can trigger unexpected sadness, anguish or homesickness. One such experience is Sad Nipple Syndrome (SNS), which many women may experience without knowing it has a name. Triggered by nipple stimulation, it remains poorly understood and largely unresearched.

Some describe it as sudden sadness or anguish, while others compare it to homesickness, nostalgia or an upsetting memory. Even putting on a shirt can trigger the sensation.

SNS is not an officially recognised medical diagnosis. Although it can affect anyone, it appears more common in women, according to the Cleveland Clinic.

Sad Nipple Syndrome Can Begin In Childhood

Also read: Lessons From The Lindsay Clancy Case: Can Families Spot Early Signs Of Postpartum Psychosis?

Some people experience SNS from childhood without understanding what is happening.

“I was probably a child when I first noticed: ‘Why does touching my nipple make me sad?’” 28-year-old Sandra told The Guardian.

She kept the experience to herself until college, when she searched for answers online. “I realized I wasn’t crazy,” she said.

The Role Of Oxytocin And Dopamine

One possible explanation involves oxytocin, commonly known as the 'love hormone'.

Dr Vladimír Kraus from the Department of Gynaecology and Obstetrics at Pavol Jozef Šafárik University suggests oxytocin may be involved because nipple stimulation triggers its release.

Oxytocin plays a role in bonding and emotional connection. It is released during physical touch and also plays a role in childbirth and breastfeeding.

Kraus theorises that changes in oxytocin signalling could trigger negative emotions associated with SNS, although this has not been established.

A study found that breast stimulation increased oxytocin levels in both lactating and non-lactating women, suggesting the response is not limited to breastfeeding.

Maureen Sweeney, a psychiatric mental health nurse practitioner and women's behavioural health specialist at the Cleveland Clinic, suggests oxytocin release may also influence dopamine production. Reduced dopamine could contribute to dysphoric feelings, although this remains a proposed explanation.

Other possible factors include postpartum mental health, body image concerns, anxiety and intimate partner violence. Sweeney also points to premenstrual dysphoric disorder (PMDD), suggesting that some people may be more sensitive to normal hormonal fluctuations.

Read More: Breastfeeding Can Help Reduce Mothers' Risk of Type 2 Diabetes, Breast Cancer and More

How Is SNS Similar To D-MER And Post-Coital Dysphoria?

Dysphoric milk ejection reflex (D-MER) causes sudden negative emotions, such as sadness, homesickness and guilt, just before or during milk letdown while breastfeeding. It can also affect the breastfeeding experience and maternal bonding.Post-coital dysphoria (PCD), meanwhile, involves sadness, anxiety or irritability after sexual activity.

While SNS and D-MER are associated with nipple stimulation, PCD occurs after orgasm. Despite the different triggers, people can experience similar emotional and physical sensations, lactation consultant Alia Macrina Heise was quoted as saying to The Guardian.

She suggested hormonal interactions may be involved in all three conditions, although their precise mechanisms remain unclear.

Is There A Treatment For Sad Nipple Syndrome?

There are no specific treatments for SNS, and more research is needed to understand its causes. However, coping strategies and psychological support may help manage the distress. Sweeney suggests cognitive behavioural therapy (CBT) as one approach to addressing symptoms, even when a therapist is unfamiliar with SNS.

Per- and polyfluoroalkyl substances (PFAS), commonly known as forever chemicals, have sparked interests of epidemiologists who are investigating their links to chronic diseases like high blood pressure, cardiovascular conditions and certain cancers.

PFAS are a large group of chemicals made by humans that have been used in industrial processes and everyday consumer products. They are found in cosmetics, kitchen supplies, clothing, carpets, upholstery, food packaging and other household materials.

They are called forever chemicals because their strong chemical bonds make them resistant to breaking down in the environment. Some PFAS can also exist in the human body, allowing exposure to accumulate over time.

At the American Public Health Association's (APHA) 2026 Annual Meeting, researchers presented findings on how people are exposed to these chemicals everyday through food and drinking water, and what long-term health consequences may be related to that exposure.

Health Problems Linked To Forever Chemicals

Some studies have identified that PFAS exposure could lead to colon and liver cancers, low birth weight, development problems in children, complications during pregnancy and other metabolic disorders. Research has also identified its exposure to cholesterol, changes in liver enzymes, reduced antibody responses to some vaccines and hypertension during pregnancy.

However, this does not establish that PFAS exposure directly causes every condition reported in epidemiological studies. Health effects may depend on the chemical type, exposure levels, duration of exposure and individual factors.

The US Agency for Toxic Substances and Disease Registry (ATSDR) states that research into PFAS health effects is in progress.

Also read: Paper Straws Have 6.33 Times Higher Carcinogenic Risk Than Plastic Straws, Study Finds

Food Is A Significant Source Of PFAS

Besides drinking water, food can also contribute to exposure, prompting researchers to investigate whether dietary habits influence the relationship between PFAS and chronic health conditions.

One study conducted in Massachusetts examined the relationship between dietary patterns, PFAS exposure and blood pressure. Researchers found stronger associations between a specific PFAS compound and high blood pressure among people who regularly consumed fish.

Yuting Wang, a postdoctoral research fellow at Silent Spring Institute and one of the researchers involved in the study, said animal-based foods appeared to contain more PFAS than plant-based foods.

One possible explanation, she suggested, was that meat consumption could increase inflammation, which may influence the relationship between PFAS exposure and blood pressure.

"Better understanding interactions among diet, PFAS and blood pressure may improve clinical recommendations to prevent hypertension," Wang said. "Future studies should account for exposure to environmental pollutants in addition to nutrient benefits of certain food," she added.

Also read: Lancet Study Finds Air Pollution & Chemical Exposures Could Add To South Asia's Diabetes & Heart Disease Burden

PFAS Found In US Drinking Water Supplies

According to the US Geological Survey, approximately 45% of drinking water samples collected across the country showed traces of PFAS. Researchers have also investigated PFAS contamination in 11 townships in southeastern Pennsylvania. Their testing found that several drinking water supplies had PFAS concentrations exceeding the US Environmental Protection Agency's 2021 regulatory limits.

The team also examined two decades of mortality data from the townships to investigate whether areas with higher PFAS levels in public drinking water has different patterns of disease and death.

Erin Kulick, an assistant professor of epidemiology and biostatistics at Temple University College of Public Health who worked on the Pennsylvania study, said, "Southeastern Pennsylvania experiences overlapping burdens of PFAS exposure and cardiovascular disease."

Scientists Are Concerned About Long-Term Exposure

PFAS contamination is a public health concern because these chemicals can remain in the environment for long periods and reach people. Some PFAS accumulate in the body, and repeated exposure may increase the amount present over time.

The National Institutes of Health identifies several health concerns linked with exposure to certain PFAS, including immune system effects, increased cholesterol, liver changes, pregnancy-related complications and some cancers.

The US Environmental Protection Agency has established legally enforceable drinking water limits for six PFAS compounds, including perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS).

Researchers say more comprehensive monitoring, better assessment and long-term epidemiological studies are needed to understand how PFAS contamination affects communities.