November 9, 2023/Primary Care

Why Do I Get Cold Sores? Common Triggers Explained

Food choices likely don’t cause cold sores — but they may help with healing and prevention

Closeup of a cold sore on a person's upper lip.

You may already know some of your triggers if you get cold sores (also known as fever blisters). Maybe you experience an annoying outbreak whenever you’re sick or work gets stressful. But could anything else be contributing, like the foods you eat?


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Internal medicine physician Rafael Fernandez Bohorquez, MD, explains what causes cold sores and what to do when you feel one coming on.

Why do I get cold sores?

Cold sores are the result of a herpes simplex virus (HSV) infection, the same virus that causes genital herpes. HSV spreads from person to person through kissing or sharing items like drinks, utensils, towels and lip balm. There’s no cure for HSV, so once you catch the virus, it stays in your body forever.

But having an HSV infection doesn’t mean you always get cold sores. “HSV can remain in a latent, or resting, state in your body for months or years,” Dr. Fernandez Bohorquez explains. “You get a cold sore when something triggers the virus to become active.”

Common cold sore triggers

Cold sores can be triggered by many different things that put stress on your body, such as:


Cold sores aren’t usually a serious health problem, but they’re uncomfortable and downright annoying. Knowing your triggers can sometimes help you sidestep an outbreak.

“We can’t always avoid cold sore triggers,” says Dr. Fernandez Bohorquez. “But if you learn your triggers, you can counteract them or start treating a cold sore early so it goes away faster.”

For example, if you get cold sores after cold or wind exposure, wear a scarf or face covering to help prevent a flare-up. If sunburn is a trigger, be diligent about sunscreen. Wear a wide-brimmed hat and use lip balm with SPF. (Bonus: you’ll also help prevent skin cancer!)

Stress management techniques can help you feel better emotionally, which could ward off at least a few cold sores.

“Exercise can reduce stress, as well as getting enough sleep and eating a healthy diet,” says Dr. Fernandez Bohorquez. “These healthy habits also boost your immune system so it can fight cold sore outbreaks.”

Should I avoid certain foods when I have a cold sore?

Along with understanding your triggers, it’d be great if eating certain foods could put a stop to cold sores for good. Unfortunately, there isn’t solid evidence to suggest that’s the case. Still, making some healthy diet tweaks couldn’t hurt if you’re desperate to eliminate that cold sore.

“Many foods contain the amino acid L-arginine, which helps the herpes virus multiply,” explains Dr. Fernandez Bohorquez. “Some research suggests that avoiding high-arginine foods could prevent cold sores or clear them up faster.”

Most foods that contain protein also contain some L-arginine, from meats to whole grains. That makes L-arginine pretty tricky to avoid completely. The better solution may be to find foods that contain higher amounts of another amino acid, L-lysine.

Foods that could help fight cold sores

Some research shows that L-lysine lowers the number of cold sore outbreaks for some people,” adds Dr. Fernandez Bohorquez. “We don’t have any large, controlled studies proving it can help, but it’s worth trying if you get frequent cold sores.”

So, when you feel that first tingle of a cold sore or know you were exposed to a trigger, try focusing on foods with more lysine, including:

Likewise, avoid foods high in arginine and low in lysine, such as:

  • Chocolate.
  • Rice.
  • Wheat and wheat products, like bread and pasta.


And if you’re thinking about lysine supplements, ask your provider first. “Supplements may not be safe for people who take medications or have certain health conditions,” says Dr. Fernandez Bohorquez. “We also don’t have large studies to prove that they help. If you get repeated cold sore outbreaks, your provider can help you find a safe and effective treatment.”

How to heal a cold sore fast

Cold compresses and numbing creams can make you feel better, but they won’t get rid of a cold sore any sooner. Antivirals are the only proven solution for getting a cold sore to go away ASAP.

“Over-the-counter antiviral creams can treat cold sores and help them clear up faster,” says Dr. Fernandez Bohorquez. “Start using the cream at the first sign of a sore. The sooner you start applying it, the more effective it will be.”

If you get frequent outbreaks, a preventive oral antiviral medication could be your BFF.

“Your provider can prescribe an oral antiviral medication if you get repeated cold sores,” Dr. Fernandez Bohorquez says. “These medications can stop cold sores from surfacing. In most cases, you try the medication for up to a year and then see your provider again to discuss how well it’s working.”

Knowledge (and regular healthcare) is power

Don’t assume you have to live with cold sores. Knowing your triggers and seeing your healthcare provider can help you handle outbreaks better.

“Antivirals can make a big difference for people who get cold sores regularly,” states Dr. Fernandez Bohorquez. “Your provider can help you find the best way to prevent outbreaks so they don’t interfere with your life.”


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