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.

Doctors in India’s southern state of Tamil Nadu surgically removed a fully developed canine tooth from the upper eyelid region of a 16-year-old boy. They described the case as the first reported instance of an ectopic tooth in the upper part of the eye socket.

The case was reported by specialists at Aravind Eye Hospital in Madurai in the journal Ophthalmology.

What Did The Doctors Find?

The teenager visited the hospital with painless swelling of his left upper eyelid that had lasted a month. He had no history of injury to the area.

During the examination, doctors noticed two firm, whitish projections beneath the swollen area near the inner side of the upper eyelid, the experts shared in the paper.

A computed tomography (CT) scan revealed a dense structure resembling a tooth, with a crown and root, originating from the roof of the left eye socket. It extended towards the tissues in front of the orbital septum, a thin barrier separating the eyelid from the deeper eye socket, and protruded outwards with two tooth-like points on its surface.

The projections' appearance and texture raised the possibility that they were teeth. Dr. Meghana Tanwar, a medical consultant at Aravind Eye Hospital, told Live Science that they had a “fairly smooth surface and were hard on palpation.”

The doctors surgically removed the structure. Examination confirmed that it was a mature canine tooth without teratomatous elements, consistent with an ectopic tooth in the upper part of the eye socket.

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What Is An Ectopic Tooth?

An ectopic tooth develops or emerges in an abnormal location. Some remain within the mouth but appear outside their usual positions in the dental arch, while others develop outside the normal arrangement of teeth.

The latter is particularly unusual. In this teenager's case, the tooth was located in the upper orbital region rather than within the normal dental arch.

Before confirming the diagnosis, doctors considered whether the projections could be associated with a teratoma, a type of tumor that can contain different tissues, including bone and tooth tissue. They also considered whether a foreign object might be lodged in the eyelid.

Imaging and examination of the removed structure helped establish that it was a mature tooth rather than tissue associated with a teratoma.

Why Is This Case Unusual?

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Ectopic teeth have been documented in several locations, including the nasal cavity, chin and maxillary sinus, an air-filled cavity within the cheekbone. Previous reports have also described teeth in the lower part of the eye socket.

However, the doctors said they could not find an earlier report of an ectopic tooth in the superior orbit, the upper region of the eye socket.

“To the best of our knowledge this is the first and only ectopic tooth reported in the superior orbit,” Tanwar told Live Science.

“This was a first not just for us but the world over,” she said of the case. “We were very surprised by it.”

What Causes Ectopic Teeth?

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The doctors could not determine why the tooth developed in this unusual location.

Possible explanations for ectopic tooth development include abnormalities during development, genetic factors, infections and physical trauma. However, the cause in this case remains unknown.

Imaging did not reveal any additional ectopic teeth. Tanwar said the likelihood of the teenager developing another such tooth was low.

Beth Dobbin, who represented Great Britain at the Tokyo Olympics in 2021, now spends more than 22 hours a day in bed.

The 32-year-old retired from athletics in April 2026, describing her illness as “serious” and “life-changing.” She was later diagnosed with myalgic encephalomyelitis (ME), a chronic condition with no known cure or specific treatment.

Dobbin reached the 200m semi-finals at the Tokyo Olympics and won bronze in the 4x200m relay with Scotland at the 2022 Commonwealth Games in Birmingham.

“It's life-decimating like I can't even put into words,” she said. “I feel like I've lost everything.”

Beth Dobbin's Diagnosis with ME

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Dobbin’s health began deteriorating after back-to-back COVID-19 and glandular fever infections in the winter of 2021-22, the BBC

reported.

She experienced worsening fatigue, slower running times and soreness in the glands in her neck and armpits. Initial tests by British Athletics doctors failed to identify the cause.

Despite her symptoms, she continued training in 2022. At the European Championships, she false-started after losing all feeling in her legs while in the starting blocks.

Her condition subsequently worsened. She struggled to stand and spent most of her time in bed. After consulting four or five specialists, she was diagnosed with ME.

Dobbin has been confined to her house and bed since then. She gets out of bed only to eat and use the bathroom. Even conversations, bright lights or loud sounds can trigger a “crash” lasting days or, in severe cases, months. She has left the house just five times this year, the report said.

She now leaves home mainly for medical appointments and blood tests. Even conversations, bright lights and loud sounds can trigger a “crash” that lasts days or, in severe cases, months. She has left home just five times this year, according to the report.

What Is ME?

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ME, also known as chronic fatigue syndrome (CFS), is a complex, chronic illness that can cause severe fatigue, pain, sleep disturbances and problems with thinking and memory. Symptoms do not improve simply with rest, and there is no established cure.

Dobbin rejects the term “chronic fatigue syndrome” because she believes it understates the severity of the condition.

“I wish it was just fatigue, that would be a walk in the park,” she said. “It's so much more than that. If I thought of fatigue in my top 20 symptoms it might just make the cut.”

She described the illness as feeling as though her entire body “is shutting down; it feels like you are a few days from death”.

More than 400,000 people in the UK are thought to have ME, although some estimates put the number above one million. The illness varies in severity, with some people continuing to work or study while others require extensive care.

Dobbin’s illness has also taken an emotional toll on her family.

“I'm just so desperate to help her but I can't because there is nothing. I'd take her anywhere, I'd take her to America if I had to, but there's nothing,” her father, Jim, said.

Beth Dobbin Aims To Raise ME Awareness

Dobbin describes her future as “very bleak” but hopes that greater awareness will lead to better treatment options.

The emergence of long COVID, which shares some symptoms with ME, has brought renewed attention to the illness and increased research funding.

She also wants to highlight the experiences of patients who are dismissed or disbelieved.

“A lot of people that have this illness that I've spoken to have said to me 'I don't get believed, people think I'm lazy'. I've never experienced one person that doesn't believe me and that's because, why would an athlete just suddenly stop after 20 years?”

Infections accounted for an estimated 2.3 million new cancer cases worldwide in 2024, or about 12% of all cancers diagnosed that year, according to a September 2026 study published in The Lancet Oncology. Among these, Helicobacter pylori (H. pylori), a bacterium that infects the stomach, was associated with an estimated 760,000 cancer cases.

A 2025 study by the International Agency for Research on Cancer (IARC), part of the World Health Organization (WHO), estimated that 76% of the 15.6 million stomach cancer cases expected over the lifetimes of people born between 2008 and 2017 could be attributable to H. pylori infection if prevention efforts do not improve.

Although infections can contribute to cancer development, they are not the only cause. Genetics, age and non-infectious factors also play a role, Dr. Vivek Kaul, Professor of Medicine in the Gastroenterology & Hepatology Division at the University of Rochester Medical Center, told HealthandMe in an exclusive interview.

“I think, generally speaking, I think H. pylori is a well-known carcinogen, mostly responsible for the development of gastric cancer,” Kaul said.

Is Cancer Increasingly Linked To Infections?

The findings highlight the contribution of infectious agents to the global cancer burden. However, Kaul cautioned against concluding that cancer is increasingly being driven by infections.

“But I don't think it's fair to say that, you know, we are moving towards a more infectious etiology for cancer,” he said.

“Cancer is a multifactorial disease state that develops, most commonly develops from genetic and from non-infectious causes,” Kaul added.

He explained that cancer development also depends on the ability of cells to defend themselves against external threats and genetic mutations.

“In many cases, cancer development comes primarily from genetic and age-related issues and boils down to the individual cell's ability, you know, to fight external attacks, such as from H. pylori type of agents or from genetic mutations,” he said.

Kaul also noted that other infectious agents have been implicated in cancer development.

How Does H. pylori Raise Stomach Cancer Risk?

H. pylori is a bacterium that infects the stomach lining and can persist for years. The infection can cause chronic inflammation and damage to stomach tissue, increasing the risk of gastric cancer.

According to scientists at the International Agency for Research on Cancer (IARC), part of the World Health Organization (WHO), H. pylori infection is responsible for an estimated 76% of stomach cancer cases worldwide. The infection often causes no noticeable symptoms, although some people may experience digestive complaints.

The bacterium can spread through contaminated food or water and close contact with infected individuals. In some cases, the infection can cause stomach ulcers. Because many infected people have no symptoms, testing may be needed to identify it.

Can H. pylori Infection Be Prevented From Progressing To Cancer?

The World Gastroenterology Organisation's global guidelines state that eradicating H. pylori before precancerous changes develop can help prevent gastric cancer. This evidence supports test-and-treat screening programmes for young adults in countries with a high disease burden and sufficient resources.

Testing can involve blood, breath or stool tests, depending on the clinical context. People diagnosed with the infection can receive treatment to eradicate the bacterium. Follow-up testing can then confirm whether treatment has worked.

Nobel laureate and gastroenterologist Dr Barry Marshall has also highlighted the potential for early treatment to reduce cancer risk.

“H. pylori is much more than an ulcer organism. If the infection persists for many years, it can cause chronic inflammation in the stomach and increase the risk of gastric cancer. That gives us an opportunity because this is a potentially preventable cause of cancer,” Marshall told PTI.

He stressed the need for wider testing, appropriate treatment and follow-up to ensure the infection has been cleared.

Other Digestive Cancers Are Also A Growing Concern

Beyond infection-associated cancers, Kaul highlighted the rising incidence of several digestive cancers.

“We know that esophageal squamous cancer is another example where we will be close to a million cases by 2035,” he said, pointing to the burden in East Asia, sub-Saharan Africa and South America, including India.

Kaul also identified liver cancer as a growing concern and noted the rise in colorectal cancer among younger people in Western countries. The increase in colorectal cancer among younger adults in the US contributed to recommendations to begin average-risk screening at age 45 rather than 50.

These trends underline the need to address infectious causes of cancer alongside other risk factors, while improving access to prevention, early detection and appropriate care.