Cold sores are caused by a strain of the herpes simplex virus (HSV-1). Whilst there is no cure, this condition is completely manageable with the right antiviral treatment.
You can purchase treatment for cold sores, here at SpeedyHealth.
Medically reviewed by Dr. Adrian Rawlinson
Written by our editorial team Last reviewed 01 April 2024
A cold sore (herpes labialis) is a viral infection caused by the herpes simplex virus (HSV). They are also known as oral herpes or ‘fever blisters’. Cold sores appear as a fluid-filled blister (or a cluster of blisters), usually on your lip or around your mouth. They can also appear elsewhere on the face, including the chin, cheeks, nose and the inside of the nostrils or the mouth.
When you initially become infected with the herpes simplex virus, It can take 1–3 weeks to show any symptoms. Once an outbreak occurs, it generally lasts between a few days and 2 weeks. The rest of the time, there are no symptoms and the virus lies "dormant".
Yes, cold sores are very common. The World Health Organization (WHO) estimated that 3.7 billion people had an HSV-1 infection in 2016. According to the National Institutes of Health, it is also estimated that nearly 90% of U.S. adults have been infected with the virus.
Cold sores are caused by an infection with HSV, of which there are two types:
Both result in similar symptoms, and cross-infections can occur.
After the first infection, the virus travels along the nerves and reaches a cluster of nerve cells called a ganglion. Over here, the virus "hides" for long periods. When triggered, the virus moves back down the nerves to the skin's surface and causes an outbreak.
Yes, cold sores are highly contagious. The herpes simplex virus can be easily transmitted to other people through skin-to-skin contact, mainly from kissing or oral sex.
It can also spread through sharing items such as toothbrushes, utensils, towels or lip balm with someone who has a cold sore.
Cold sores are contagious from the moment you first feel a tingling sensation (before the sores develop) or any other signs of a blister forming. They will continue to be contagious until the cold sore has completely healed.
Finding out what triggers a cold sore can help prevent outbreaks in the future. An outbreak is most likely to occur when you’re unwell or stressed. This is because your immune system is weakened and less able to fight off the virus.
Other triggers for an outbreak include:
Some people are more at risk of developing multiple cold sores outbreaks if they are immunocompromised.
There are several stages of a cold sore outbreak, each marked with different symptoms.
Before cold sores are visible, many people experience a prodromal phase which can last for a few hours up to a couple of days. During this phase, you may experience the following sensations on or around the lips and mouth:
Small, fluid-filled blisters will appear on the areas where you felt the prodrome symptoms. These are painful and usually appear around the lips. Less commonly, they can occur around the nose, cheeks or inside the mouth.
These blisters will eventually rupture and weep, releasing clear fluid. This leaves shallow, open sores or ulcers. This is one of the most contagious stages and is often when the virus spreads more easily.
A scab will form over the open sores to protect the skin underneath. It may become dry and very itchy. Sometimes, the blisters can crack and result in some bleeding from the scab.
Over time, the scab will get smaller and eventually disappear. Most cold sores should heal within 10 days. The entire process usually takes about 1 to 2 weeks from the onset of symptoms.
For many people, cold sore symptoms are more severe the first time they have an outbreak. If this is the case, you may experience other symptoms including:
Symptoms tend to be less severe after each outbreak. If you notice your cold sore doesn’t heal after 10 days, or your symptoms get worse, you should consult your doctor.
Once you are infected with the herpes simplex virus it stays hidden in your nerves for the rest of your life. This doesn't mean you will have continual blisters, in fact, the virus lays dormant for long periods.
HSV can become active again from time to time causing an outbreak. Certain triggers prompt an outbreak, and over time these become easier to identify and avoid. During an outbreak, the fluid-filled blisters will usually show up in the same places where you may have had a previous infection.
Most people don't get more than one outbreak of cold sores per year, however others experience outbreaks often.
Your doctor can determine if you have a cold sore by examining the affected area and asking about your symptoms. They may also swab the sore to test the fluid for the herpes simplex virus.
Although complications from cold sores are rare, they can include:
Although you can’t cure oral herpes, there are many effective treatments available to help with symptoms and shorten the duration of outbreaks.
One way to treat a cold sores outbreak is by using antiviral medication as soon as you feel the prodromal symptoms (tingling and itching). On prescription, you can get Valacyclovir tablets to treat and prevent outbreaks.
Other treatment options include different antivirals such as Famciclovir (Famvir) and Acyclovir (Zovirax). These are available in a range of forms such as creams, tablets or capsules.
There are certain things you can do yourself to prevent uncomfortable symptoms, these include:
To avoid spreading the virus while you have a cold sore, you should:
The main way to prevent cold sores outbreaks is to understand what your triggers are. For example, if you find that sunlight triggers your cold sores outbreaks, then make sure to apply a lip balm containing SPF.
You can purchase prescription-strength antiviral tablets online here at SpeedyHealth for the treatment of cold sores. You will just need to complete a quick, confidential medical questionnaire which will be reviewed by one of our registered doctors.
If you are suitable for treatment, your medication will be dispensed and dispatched from our pharmacy to your doorstep with speedy delivery.
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