Why Do I Get Cold Sores When Sick? Can They Be Prevented?

It may not come as a big surprise that ‘cold sores’ have been given their name for a good reason. Many people experience outbreaks of cold sores when they’re sick. The relative term here, however, is ‘sickness.’ And it can come in many different forms.

Cold sores also have different reasons for popping up. So, it’s important to understand exactly why people get cold sores when sick. Is there actual scientific proof to such a thing, or is it just a coincidence?

Let’s take a closer look at why you might get cold sores when you’re sick. Additionally, we’ll go over a few of the different ways you might be able to prevent them from taking over when you aren’t feeling your best.

Does Being Sick Cause Cold Sores?

In short, yes and no. Being ill, in any way, isn’t actually what will cause a cold sore. Cold sores are the herpes virus. They are classified as HSV-1, which is different from the virus that is known as a sexually transmitted disease (STD). However, once the herpes virus is inside your system, that’s where it stays. Typically, it will remain dormant. However, certain things work as ‘triggers’ that can cause flare-ups.

So, while being sick isn’t what causes cold sores to pop up, it can certainly be a trigger. This happens because your immune system is compromised. Just about any sickness can act as a trigger. A common cold, the flu, or even a fever can work against your body. As your cells work to fight back against illness, they are compromising in other ways. This can make it easier than ever for a cold sore or fever blister outbreak to occur.

Aside from the more common forms of sickness, there are other triggers linked to cold sores, as well. They all deal with your body’s immune system, and could all be linked to a certain type of ‘sickness.’ So, recognizing different situations can help you to prepare, and prevent, as much as possible.

How Can My Immune System become Compromised by Illness?

Now that you know that it’s your immune system that fights back against cold sores, you can better understand other ways in which it might be compromised. You might view all of these instances as a type of ‘sickness.’ At the very least, most of them can be connected to other types of illnesses. In that regard, it makes sense that they can also be strong triggers for cold sores.


Stress can wreak havoc on our bodies. We tend to think of it as an emotional thing, but there are so many physical factors that go along with it. Yes, a weakened immune system is one of them. When we are too stressed out, our body responds by working overtime, which can wear us down, and allow us to become sick. It’s a perfect opportunity for a cold sore to slip in and appear.

Fatigue & Tiredness

When you’re sick, you’re often feeling exhausted. But, being too tired can also make you sick. Fatigue is such an easy way for our immune systems to become weakened. When our bodies aren’t getting the rest and recuperation they need, it’s easy to become sick. It’s even easier for our immune systems to slow down until they can recharge.

Hormonal Changes

These changes will typically affect only women but can do more than you might think. A shifting of hormones in the body (during menstruation, pregnancy, etc.) can also cause the immune system to weaken. This is just one of the reasons cold sores during pregnancy is common.

As you can see, there are plenty of links to a weakened immune system. Day-to-day living offers up so many risks that we typically don’t fully consider. Thankfully, most of these problems and sicknesses can be treated. Better yet, you can work to prevent them in the first place.

How to Prevent Cold Sore Outbreaks

If you find that getting a cold, the flu, or any other changes in your body listed above can trigger cold sores for you, the best thing you can do is to try to prevent them from happening. That can be easier said than done, sometimes. However, most prevention steps are fairly simple. They are habits you can introduce into your everyday life. Or, simply be more conscious of them as you go through your day.

Flu Vaccinations

Getting your yearly flu shot is a great way to ward off the illness. If you’re not into needles, there are now nasal spray options. You may never get the flu, even without a shot. But, if you’re prone to cold sores, it’s worth it. It is painless, low-cost, and effective at keeping you healthy during cold and flu season.

Wash Your Hands

This may seem obvious, but it’s so important. Washing your hands could be the single most important preventative measure on this list. We touch our faces multiple times a day, without realizing it. Think about everything else you’ve touched today. Usually, when we think about both, it’s easy to cringe a bit. So, be sure to wash your hands as much as possible throughout the day.

Eat for a Healthy Life

Your diet can have a lot to do with how you feel. It can also have a lot to do with how your body responds to illness. Eating healthy foods goes so far beyond weight management. So, eat for your health, and avoid more cold sores.

Why Do I Get Cold Sores When Sick?

Rest Your Body

As listed above, fatigue and stress are two big triggers for cold sores. Make sure your body gets adequate rest each day, so it can repair itself, and become stronger. The stronger your body, the stronger your immune system.

The Link Between Cold Sores and Sickness

There are some links between getting sick, and getting cold sores. While sickness isn’t the cause, it can be a trigger for an outbreak. Do what you can to recognize any potential triggers within yourself. Then, take preventative steps to fight back. The stronger your body and immune system are, the less you’ll have to worry about a cold sore outbreak.