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.

For many men trying to conceive, testosterone sounds like an obvious answer. It is often linked with strength, vitality, and male health, so the assumption is that higher levels must also support fertility. In reality, the opposite is often true. Medical experts caution that using testosterone, especially without supervision, can interfere with sperm production and quietly lower the chances of becoming a father.

To know more about the same, we got in touch with Dr. Ambavarapu Divya Reddy, Fertility Specialist, Nova IVF Fertility, LB Nagar, Hyderabad.

Can Increasing Testosterone Help You Conceive?

Dr. Ambavarapu Divya Reddy said, the short answer is no. Testosterone is a male sex hormone, but it does not support fertility in the way many people assume. In fact, taking testosterone can work directly against sperm production. For men who want children, using testosterone without expert guidance can quietly reduce fertility rather than improve it. Here is what doctors want patients to understand.

Why Testosterone Does Not Boost Fertility?

Testosterone is fundamentally opposed to male fertility when taken from outside the body. Using testosterone injections, gels, patches, or pellets suppresses the natural communication between the brain and the testicles that keeps sperm production going. Dr Reddy said, “When this system is switched off, sperm counts fall and in some cases drop to zero. Fertility declines instead of improving.”

This is why men who plan to have children should never begin testosterone therapy without speaking to a specialist.

How Does Sperm Production Work?

Sperm are produced in the testicles with the help of testosterone that is made inside the testicles themselves. This internal testosterone is tightly controlled by the brain through a hormone called luteinizing hormone, or LH.

Dr Reddy told us, when external testosterone is introduced into the body, the brain senses enough hormone is present and stops releasing LH. As a result, the testicles reduce their own testosterone production and sperm production slows or stops altogether.

In real-world practice, many men on testosterone therapy develop extremely low sperm counts or complete absence of sperm, known as azoospermia, often without any obvious symptoms. This is a well-recognised cause of male infertility and one that is largely preventable.

Low Testosterone And Fertility: What Doctors Do Instead

If a man truly has hypogonadism, meaning he has symptoms along with low testosterone levels on blood tests, treatment is still possible but must be handled carefully. Current guidelines from the AUA, ASRM, and endocrine societies strongly advise against starting standard testosterone replacement in men who want children in the near future.

Instead, specialists use treatments that can raise testosterone levels while allowing sperm production to continue. These include clomiphene, human chorionic gonadotropin or hCG, and other targeted therapies that stimulate the testicles rather than shutting them down. Updated guidance for 2024 and 2025 stresses identifying the cause of low testosterone and choosing options that protect fertility.

If you think you have low testosterone but want children

a) Do not self-prescribe testosterone.

b) Consult a reproductive urologist or endocrinologist.

c) Ask about fertility-preserving treatments such as clomiphene or hCG and consider sperm banking if timing matters.

d) If you have already used testosterone, request a semen analysis and hormone tests. Acting early can help guide recovery or fertility treatment.

Testosterone may seem like an easy solution, but external testosterone is a common and avoidable cause of male infertility. If having children is important to you, proper testing and specialist care matter. The treatment that relieves symptoms is not always the one that protects your ability to become a father.

A little-known virus is spreading steadily across different parts of the world, prompting growing concern among health experts. Often described as “untreatable” because there is no targeted antiviral medicine available, adenovirus is drawing attention due to how tough it is and how quickly it can pass from person to person.

Eric Sachinwalla, medical director of infection prevention and control at Jefferson Health, has cautioned that while most healthy individuals develop only mild illness, people in high-risk groups may face more serious health problems. This raises an important question: just how contagious is this mystery illness that is spreading?

Adenovirus: How Contagious Is It?

Yes, adenovirus is highly contagious and spreads with ease in several ways. It can pass through respiratory droplets released during coughing or sneezing, close physical contact such as hugging or shaking hands, and contact with contaminated surfaces like toys and towels.

It can also spread through fecal matter, particularly during diaper changes, and in some cases through water. According to the CDC, the virus spreads quickly in crowded settings such as schools and daycare centres and can survive for long periods on surfaces, making good hygiene especially important for young children and people with weakened immune systems.

Who Do Adenoviruses Affect Most?

Adenoviruses can infect people of all age groups, but they are most commonly seen in children under the age of five. In babies and young children, the virus often spreads in daycare environments where close contact is common. Children are also more likely to put shared objects in their mouths and may not wash their hands as regularly.

Among adults, adenoviruses tend to spread in crowded living conditions. People staying in dormitories or military housing may have a higher risk of infection. The virus is also known to circulate in hospitals and nursing homes, as per CDC.

Those with weakened immune systems are more likely to become seriously ill from an adenovirus infection. This includes people who have undergone organ or stem cell transplants, as well as those living with cancer or HIV/AIDS. Individuals with existing heart or lung conditions may also face a higher risk of severe illness.

Adenovirus: What Are The Symptoms Of An Adenovirus Infection?

The symptoms of an adenovirus infection depend on the part of the body affected. Most commonly, the virus targets the respiratory system. When it infects the airways, it can cause symptoms similar to a cold or the flu. These may include:

• Cough.
• Fever.
• Runny nose.
• Sore throat (pharyngitis).
• Pink eye (conjunctivitis).
• Ear infection (otitis media).
• Swollen lymph nodes.
• Chest cold (bronchitis).
• Pneumonia.

Adenoviruses can also infect the digestive system. When this happens, diarrhea may occur, along with gastroenteritis. Gastroenteritis is inflammation of the stomach or intestines and can lead to stomach pain, diarrhea, nausea, and vomiting.

In rarer cases, adenoviruses can affect the bladder or the nervous system. Infection of the bladder may result in urinary tract infections. When the nervous system is involved, it can lead to serious conditions affecting the brain, including encephalitis and meningitis.

Influenza, commonly called the flu, is a respiratory infection caused by the influenza virus. It is contagious, which means it passes easily from one person to another. Although influenza viruses can circulate throughout the year, infections are seen more often during the fall and winter months. This time is known as the flu season. As flu cases are rising across many parts of the US and UK, here are a few key points to understand, from the incubation period to how easily the virus spreads.

What Is The Flu (influenza)?

The flu is an infection caused by the influenza virus. It usually leads to symptoms such as body and head aches, sore throat, fever, and breathing-related discomfort, which can sometimes become serious. Flu cases tend to peak during the winter months, when large numbers of people may fall ill at the same time, a situation described as an epidemic, according to the Cleveland Clinic.

Flu: What Is The Incubation Period Of The Flu?

The average incubation period of the flu is around 2 days, though it can vary from 1 to 4 days. In simple terms, this means most people begin to notice flu symptoms a few days after the virus enters the body.

When Does The Flu Become Contagious?

After catching the flu virus, a person can start passing it on to others about 1 dayTrusted Source before symptoms appear. Keep in mind that the usual incubation period is about 2 days. So, if someone is exposed to the virus on a Saturday morning, they may already be able to spread it by Sunday evening. By Monday afternoon, flu symptoms are likely to show up. These symptoms can be mild or severe.

Some people may not develop symptoms at all, but they can still spread the virus. The flu is usually most contagious during the first 3 days of illness. After symptoms begin, a person may continue to infect others for another 5 to 7 days. Children, older adults, and people with weaker immune systems may remain contagious for a longer time.

Flu Symptoms 2025: Early Symptoms You Need To Take Care Of

Unlike the common cold, which tends to develop slowly, flu symptoms often appear suddenly.

Common symptoms include:

• feeling extremely tired, exhausted, or weak
• headache
• blocked or runny nose
• sore throat
• dry cough
• muscle and body aches
• fever or chills, although not everyone gets these
• vomiting or diarrhoea, which is seen more often in children

Most people start to feel better within a few days to two weeks. However, some individuals may need antiviral medication, particularly those at higher risk of serious complications.

How Does The Flu Spread?

The flu mainly spreads through tiny respiratory droplets released when an infected person coughs or sneezes. In crowded places, these particles can be inhaled by others, leading to infection. The virus can also spread by touching objects or surfaces that carry the virus, such as door handles or shared personal items. Outside the body, the virus can survive on surfaces for up to one day.

If someone touches a contaminated surface and then touches their eyes, nose, or mouth, the flu virus can enter the body and cause infection.