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Causes of Cold Sores

Causes of Cold Sores

What Are Cold Sores – Causes of Cold Sores

First we need to understand what a cold sore is and how it works. HSV-1 or Cold Sores is a strain of the herpes virus. Research has shown that between 50-90% of all American carry the antibodies to HSV-1.

Herpes has evolved over millions of years and has learned to live within the host (us) without doing very much to alert the human immune system. It has found the best ways to use us to reproduce its own species. It has adapted to infect areas that provide easy transfer and replication by utilizing the human oral and sexual areas of the body.

Once the Herpes Virus enters a host it travels down a nerve to hibernate. This helps it avoid a full force attack from the human host’s immune system. Whenever the Herpes Virus senses that the host immune system is preoccupied or weakened it heads to the skin’s surface to seek a new host to infect.

After infecting the surface skin cells it retreats back into hibernation before the immune system can attack and destroy it. (This ability to run and hide is why an official medical cure has not been found for the Herpes Virus).

We are unfortunately left with the dreadful symptoms of the Virus to contend with. The Herpes Virus is a true opportunist. It only attacks the surface of the skin when the host immune system is in a weakened condition. When the Virus senses an opportunity it moves to the skin’s surface and infects the local skin cells.

The body recognizes this as an invasion from the outside rather than from the inside. So then, the immune system sends help to the damaged area only rather than internally tracing down the actual virus that is hiding within the body.

Because the body is fooled it sends the killer white cells to the skin rather than seeking out and eradicating the hiding Herpes Virus, it then escapes unharmed while the skin erupts in a battle against the virus. The battle creates an increasingly tender red area as the skin becomes inflamed but the body only acts when the Virus causes the skin to open or as the blisters begin to form and pop.

At this point the body is not only fighting the Virus but is now engaged in a struggle against unwanted bacteria that has infected the area. The battle between the white cells surrounding the virus causes dead virus cells and dead bacteria to become a swelling infection that becomes covered with drying cells creating a scab (figure 1). Eventually the white cells beat back the virus and invading bacteria. When the battle is over the red cells come in to repair the damaged skin.

The goal then becomes improving the immune system so that the virus has NO opportunity to strike at all.

The Causes Of Cold Sores

Cold sores, commonly known as fever blisters, are small blister-like lesions that occur in the face as well as inside the mouth. The areas in which the lesions arise are usually itchy, painful and have a burning sensation. The blisters form and grow in size until they burst spontaneously or in response to scratching. This leaves behind crusted lesions, which heal after several days or weeks with or without treatment.

The commonly involved areas on the face are vermiform border of the lips, the cheeks and the chin. In severe cases, the cold sores or blisters can be found on the gums and even the roof of the mouth (the palate). The lesions usually crust over and remit or heal but this does not mean the infection has been eliminated.

What Causes Cold Sores

There are two forms of this disease. There is primary infection and secondary infection. These have different causes or triggers and therefore need to be discussed individually. By knowing the causes of each of these forms, the right preventive measures can be taken to avoid further transmission and re-infections.

The Causes of Primary Cold Sores

Primary cold sores are caused by a virus called Herpes Simplex Virus. There are two strains of this virus, herpes simplex virus type 1 (HSV-1) and herpes simplex virus type 2 (HSV-2). The oral lesions are usually caused by HSV-1 and infrequently by HSV-2.

The virus enters the body through a breech in the integrity of the skin around or inside the mouth. Inside the body, it enters nerve cells and triggers an immune response known as inflammation. This is what causes the swellings, redness and pain characterizing the cold sores or fever blisters. Irritation of the involved nerve endings is what causing the tingling, itching and the burning sensation.

Primary infection is usually spread through contact with an infected person. The common routes of transmission include contact with the sore or infected fluid from the blisters. This can happen when you share personal items such as utensils, razor or toothbrush, touching the saliva of an infected person or kissing an infected individual.

A mother or a father can spread the virus to his or her child by kissing him or her. Once you are infected, the lesions may not be restricted to the oral areas. The blisters may involve other areas of the body if you touch the lesion then touch another part of the body with the same hand having the viruses.

Lastly, primary cold sores can also result from infection by HSV-2. This occurs when a person with genital herpes transfers the viruses to another person’s mouth through oral sex. The symptoms of primary herpes are similar no matter the strain of the virus that has caused them.

The Causes Of Secondary Cold Sores

Usually the primary infection lasts a couple of days then remits with or without intervention. If proper treatment is carried out then the viruses may be eliminated from the vesicles. If nothing is done or the treatment is ineffective, the viruses enter a dormant stage in which they stay inactive in the nerve endings until re-infection is triggered by another stimulus. This is referred to as secondary herpes virus infection.

Many things can activate the dormant viruses leading to recurrence of the symptoms associated with the primary disease. The following are the common triggers of the secondary cold sores.

Mental stress

Social or emotional stress has been associated with reactivation of the dormant or latent HSV-1 infection. Experts believe that stress induce hormonal changes in the body that influence the growth and development of the HSV-1. What this means is that if you had an infection that apparently resolved; you would see the symptoms recur if you develop mental stress, depression, anxiety and other related mental health problems.

Illness and fever 

If you already have the viruses in your body, fever and any other illness can cause reactivation. Perhaps the reason why it was named cold sores is that the infection is triggered by cold or flu. This is especially true if the cold or flu is associated with fever. Professionals believe that the connection has everything to do with immune modulation. Your immune system contributes in keeping the viruses in check. If you contract a cold or flu, your immunity will be tremendously reduced giving the viruses the opportunity to multiply.

Sunlight exposure

Your body needs some amount of exposure to sunlight to work better and synthesize vitamin. However, in those with latent cold sores sunlight can do more harm than good. Sun exposure reactivates the viruses leading to recurrence. While it is necessary to expose your body to sunlight, ensure that you only expose yourself for a short time. Ultraviolet radiations may damage the skin and alter the metabolic machinery of the viruses thus reactivating them.


All normal women in the reproductive age usually menstruate on a monthly basis. The problem is, for women with latent colds sores, menstruation can be a trigger. However, not all menstruating women with the latent infection will have their viruses activated. Whether or not this happens will depend on other factors. Experts in health field believe that the cause of reactivation is the hormonal as well as immunological changes associated with this physiological status.


Pregnancy is another state characterized by hormonal changed and reduced immunity. If you get pregnant while you have the latent form of HSV-1 ore HSV-2, chances are that your herpes will be reactivated. The problem is that if you have this infection during pregnancy, the newborn baby may be predisposed to cause serious health problems at this early age.

From the above discussion, it is obvious that the causes of cold sores are easy preventable. If treatment is started early in the primary phase, then the viruses will not enter the latent stage. In those with latent HSV-1 or HSV-2 infection, reactivation is easily preventable except in the cases where normal physiological changes are responsible as in menstruation and pregnancy. However, transmission to the newborn can be prevented by treating the expecting mother.

Find Out Powerful Information On What Causes Cold Sores

There are many things that can contribute to an outbreak and it also varies from people to people. So when asking the question ‘what causes cold sores,‘ you need to first find out what are the causes of your cold sores and then you will be better prepared to treat and prevent it. We will list some of the main causes of an outbreak and hope that this information will assist you in overcoming this horrible virus.

Diet – This may sound almost hard to believe, but experiments have proved that McDonald’s food is another thing that can activate the virus. It is believed that the grease in their food is what causes cold sores. If you are in doubt give it a test and see for yourself, because different things cause outbreaks for different people.

Citrus fruits are also something that can lead to an outbreak of cold sores. This is because citrus foods are acidic and cold sores lives and blooms in an acidic environment. You also want to avoid anything with vinegar like mustard or ketchup because these condiments, believe it or not, are also what cause cold sores.

Dehydration – Since dehydration is also known to cause cold sores, one of the best preventions is keeping your body hydrated. Water is the best beverage to cleanse the tissues thus keeping the virus under control.

Weather Conditions – Weather conditions are another key factor that can lead to the formation of a cold sore. You have to pay close attention to the time and condition of the weather so you can be prepared and stop the virus before it triggers.

Using Utensils – Eating from a fork or spoon that has not been properly cleaned can cause cold sores. This can happen at a restaurant because thousands of people eat from the same utensils and sometimes they are not sanitized as they should be. So you should consider using only plastic forks or spoons when out eating.

How A Weak Immune System Can Cause Cold Sores

Keeping our bodies healthy is the number one defence against, not only cold sores, but other illnesses, sickness and disease. In terms of what we are seeking to accomplish: ridding our lives from outbreaks, a strong immune system is CRUCIAL in the battle against cold sores. The immune system is designed to defend us against millions of opportunistic bacteria, microbes, viruses, toxins and parasites just waiting to invade our bodies.

Your immune system works as your guardian defender. It is armed with special cells called white blood cells, antibodies and chemicals that activate protective responses all within specialized organs and complex vessels called the lymphatic system.

Through a series of steps called the immune response, the immune system attacks organisms and substances that invade body systems and cause disease. When the immune system is weakened, the body is susceptible to disease. Like most systems in the body, the immune system is dependent on proper nutrition.

Unfortunately, the immune system can be damaged by many lifestyle choices and environmental influences. Below are a few of the factors that commonly cause immune system collapse:

1. Over-the-counter drugs such as acetaminophen, ibuprofen, corticosteroids

2. Lack of rest – not enough sleep

3. Excessive alcohol use, see note

4. Nutritional deficiencies, particularly Vitamin A or C or zinc

5. Pesticides and environmental chemicals

6. Trauma, e.g., accidents, major surgeries

What Causes Cold Sores?

Herpes simplex-1 is a virus that is responsible for cold sore infections. Also known as herpes labialis, this strain of virus specifically targets the oral tissues. Herpes simplex -2, on the other hand, is the primary cause for the development of genital herpes. However, it is important to know that both of these viral strains can affect any part of the body, at any time.

Interestingly, about 90% of people in the world carry HSV-1. This is because most individuals are highly likely to acquire the virus as small children, often through affectionate contact with their parents. However, only a third of these people experience cold sore outbreaks. This means that it is possible to carry HSV-1 without ever experiencing a cold sore.

Weakened Immune System

The appearance of a cold sore is often dependent on the presence of HSV-1, as well as some kind of triggering condition. Often, herpes simplex strains are kept dormant due to the influence of the body’s immune system.

However, as soon as the immune system weakens, this “hold” begins to loosen, galvanizing the virus into activity. When this occurs, HSV-1 emerges from the nerve tissues of the body. It travels along the nerve ganglia to the surface of the skin, where is commences its reproductive cycle in the form of a cold sore.

There are a wide range of triggers that can kick off the cold sore cycle. Often, common sense dictates that anything that negatively impacts on the body’s immune system is a cold sore cause. For instance, during bouts of flu or colds, the body is also vulnerable to a range of secondary infections, like fever blisters.


People often tend to develop fever blisters in the wintertime, when the weather is at its coldest and when the immune system is often under immense strain. Emotional stress and mental stress can also diminish the efficacy of the immune system, thereby encouraging the development of HSV-1. Fatigue, malnutrition, and inadequate hygiene can all contribute to cold sores, too.


The virus is also susceptible to hormonal changes in the body. Teenagers experiencing puberty are often more likely to experience cold sore outbreaks. Women also develop fever blisters in the hormonal fluctuations associated with menstruation.


There are also certain external environmental factors that cause cold sores. For instance, physical trauma to the face – in the form of an injury – can rupture the skin and expose it to all kinds of infections. Exposure to intense amounts of ultra-violet radiation, in the form of sunburn, can also catalyze the emergence of fever blisters.

It is always helpful, therefore, to stem these triggers by taking some precautionary measures with regards to cold sores. A balanced, vitamin enriched diet will do wonders for the immune system, as will rest and exercise. Relaxation strategies, such as yoga and meditation, have helped people prone to stress. It is also a good idea to cover the skin with high SPF sun lotion, so as to avoid some of the complications caused by prolonged UV exposure. All of these tactics should reduce the chances of a bad cold sore outbreak.

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