Does the Sun Make Cold Sores Worse?

Does the Sun Make Cold Sores Worse?

Sunny days call for sunbathing, beach days, and outdoor activities. But all doesn’t go according to plan. If you have cold sore problems, you may want to rethink your plans. But, does the sun make cold sores worse?

Yes, while sun exposure cannot ‘cause’ cold sores, it can undoubtedly trigger and worsen them. The ultraviolet (UV) rays from the sunlight damage our skin barrier. More importantly, they activate dormant viruses that cause cold sores. So if you have cold sore problems, you need to take proper measures.

Read along to find out all about cold sores from sun exposure! Knowing about the causes can help you figure out ways to heal cold sores.

What is a Cold Sore?

Cold sores are more commonly known as fever sores. They’re a group of painful tiny blisters that usually appear around the lip area. You may also get them near your nose and cheeks.

Cold sores are caused by Herpes Simplex Virus (HSV-1) virus. Once you get the virus, it can stay on your skin forever and reappear if triggered. Most people contract HSV-1 when they are young through skin contacts such as kissing, playing, etc.

The first symptom is the tingling/itching and redness of the skin. Within 12-24 hours, painful, swollen blisters will form. The blisters will let out fluids for the next 2-3 days. After this, the blisters start to dry out, and scabs form on them. These scabs may crack and bleed before they fall out, completing the cycle of blisters.

Does the Sun Make Cold Sores Worse?

Yes, the sun makes cold sore worse.

While the sun doesn’t “cause” cold sores, sunlight can trigger outbreaks or make them worse if you already have the virus. Staying in the sun too long or being exposed to too much sunlight can trigger your cold sores more than you can imagine.

The ultraviolet (UV) ray is the leading cause of cold sore triggers. UV rays can be damaging to the skin barrier. Moreover, UV rays play an active role in triggering the dormant HSV virus.

Prolonged exposure to sunlight can cause stress, chapped lips, exhaustion, etc. All these can contribute to triggering cold sores. Staying in the sun for longer requires wearing sunblock. If we are not careful or aware of our skin type, these sunblocks can make our skin greasy by blocking our pores. Greasy skins are more prone to cold sores breaking out, as this virus prefers wet/damp spots to thrive.

Protection and Prevention

Prevention is better than cure. If we can keep our triggers in check, we will not need to worry about cold sores as much. Here are a few protective measures you can take to prevent the sun from triggering a cold sore.

1. Stay in the Shade

Starting with the obvious- since sunlight triggers cold sores, don’t bask in the sun. Of course, we are not telling you to spend your summer vacation completely locked indoors! You can enjoy the summer sun, the beach, and your summer vacation. But, make sure you are not directly exposed to sunlight for an extended period. Use personal umbrellas, caps/hats, etc. Make use of the shaded beach chairs when you are at the beach. Stay in the shade for as long as possible.

2. Sunscreen

A great way to block the harmful sun rays (UV rays) that trigger the cold sore is to wear sunscreen. Usually, SPF 30++ and higher work just fine. But to be on the safe side, you can pick SPF 50++. One thing to note here is that you should choose sunscreen or sunblocks that suit your skin. If you don’t, your pores will become clogged. As a result, your skin will be greasy and oily. Greasy or oily skin can harbor and trigger cold sores very easily.

3. Lip Balm

Most cold sores appear near and around the lip area. Cracked and damaged lips can easily harbor HSV-1s. Make sure you’re keeping your lips moisturized. For extra protection, buy lip balms with SPF (YES, that’s a product you can and should buy).

4. Boost Your Immunity

Before summer vacation, start working on your diet and meal plans. Boost your immunity system by taking nutritious food- especially the ones that have vitamin C.vitamin C works great against cold sores and blisters, even if it hurts a lot. Take a lot of lemons, oranges, and other citrus fruits.

5. Stay Hydrated and Rested

Staying in the sun can cause you stress and damage your skin barrier. Drink as much water as possible to improve your overall skin health and hydration. Resting can help reduce your stress, which in turn reduces the chance of sunlight triggering your cold sores.

Healing and Treatment

You may still get cold sores after staying cautious and careful. Now, let’s see what steps we can take to treat and promote the healing of our cold sores.

1. Apply Ice

Applying ice can help with your inflammation. Cold sores can undoubtedly be painful- the cold from the ice will help you tackle the pain and inflammation. You can also try applying cold aloe gel or washing the blister with cold water. However, make sure to pat down or air-dry the affected area afterward gently. HSVs love damp skin, as they can thrive better in them. So, it is just as essential to keep your blister dry after applying ice, cold water, etc.

2. Ointments, Medicines, and Creams 

You can find many over-the-counter (OTC) solutions for cold sores. Starting from ointments to gels, creams, medicines, etc. For pain relief, creams containing benzocaine or lidocaine can help tremendously. To treat the blisters, find an ointment containing docosanol. Home remedies containing jojoba, raspberry leaf extract, etc., can help keep the cold sore under control.

3. Keep It Dry

As much as we hate to say it, you need to let your blisters dry. It is part of the healing process. The sooner it dries and the scabs fall off, the sooner you’re free and healed. Make sure to keep the blisters dry. Some even suggest mild sunlight (near sundown) to dry out the blisters and scabs easier and faster.

4. Stay Well Rested and Hydrated

As mentioned before, staying hydrated promotes your overall skin health. Resting also promotes healing. So, drink lots of fluid, nutritious food, and rest. Give your body time to heal itself.

Bottom Line

Summer means vacation, basking in the sun. However, not all of us have the privilege to enjoy everything to the fullest.  Sun exposure can trigger and worsen your cold sores, as UV rays can damage the skin and activate the virus causing them.

We hope this article helps answer your question, “does the sun make cold sores worse?” If you have any more questions, let us know!


1. Can I pop my cold sore?

Technically, you can- but you definitely should not. Cold sores are blisters filled with fluid containing bacteria. Popping them would cause the fluid to release infectious fluid, and you may end up getting more blisters. Moreover, your healing process will slow down, and you will be in much pain.

2. How long are cold sores contagious for?

Cold sores are contagious until they go away or heal completely. This process can take up to two weeks. A cold sore can spread from person to person within this time frame via skin contact.

3. Can cold sores spread through pillows?

No, cold sores can only spread through direct skin contact with the affected area. No other product can carry the virus unless there is warm blister puss on it.