The Runner’s Itch Is Real: Here’s What Causes It (+ How To Treat It)

Feeling itchy or tingly when you start your run? You're not alone.

The aptly named condition runner’s itch refers to an itching sensation that typically occurs on the legs and/or stomach while you are running.

That said, according to the Mayo Clinic, you can also experience the symptoms of a runner’s itch, such as itchy legs, while doing other types of cardio exercise aside from running.

The good news is that while experiencing an itchy feeling—particularly itchy legs while running—is certainly unpleasant and can impact your focus during your workout and your motivation to follow your training plan, runner’s itch usually isn’t a cause for concern. 

Moreover, there are some simple and often effective treatment and prevention strategies for runner’s itch.

In this runner’s itch guide, we will discuss what runner’s itch is, the most common causes of itchy skin while running, and tips to prevent itchy legs or an itching sensation while running.

A runner scratching their side.

What Is Runner’s Itch?

Runner’s itch is an itching sensation that typically occurs on the legs and/or stomach while you are running.

Itchiness on your stomach or itchy legs while running can be a total nuisance.

Generally, an itching sensation or feeling of itchiness while running or exercising is benign, but in some cases, because runner’s itch isn’t fully understood, you may need to work with your healthcare provider to determine why you are getting itchy during exercise.

This is because there are several potential causes of runner’s itch, and even within the identified runner’s itch causes, the pathophysiology (the reason that your legs itch while running) isn’t entirely clear.

That said, here are some of the most common causes of generalized itchiness, an itchy abdomen, or itchy legs, to answer your question, why do I have itchy legs when I walk or run?

A runner scratching their legs.

Causes Of Runner’s Itch

#1: Increased Blood Flow

Particularly for new runners or those coming back from time off, an itching sensation in the legs while running can be due to nerves being stimulated when blood flow increases.

With any type of cardio exercise or aerobic physical activity, heart rate increases so blood flow to the smaller blood vessels like arterioles and capillaries increases.

For people who have been sedentary or not doing cardio exercise, many of these smallest blood vessels surrounding the muscles are not perfused with blood flow on a day-to-day basis at such a high rate.

This is because the muscles don’t need to use every “roadway“ to get oxygen if you are not engaging in regular exercise.

Once you start exercising, there is an increase in circulation and many of the blood vessels run very closely with nerves. Some of these nerve cells relay sensory information such as an itchy feeling or itchy sensation. 

As the blood vessels expand or “wake up,“ the nerves can also be stimulated or irritated in a way, causing a perception of itching when running.

While this tends to happen more commonly in new runners, some people who have more sensitive nerves may also experience itching when running due to the same mechanisms of increased blood flow around the nerves.

A runner scratching himslef.

#2: Histamine Release

We often hear about the histamine response in relation to an allergic reaction, but studies1Luttrell, M. J., & Halliwill, J. R. (2017). The Intriguing Role of Histamine in Exercise Responses. Exercise and Sport Sciences Reviews45(1), 16–23. https://doi.org/10.1249/jes.0000000000000093 have found that exercise may also increase the release of histamines.

Histamines cause the blood vessels to expand and can also trigger an itchy sensation because of inflammation and irritation of nerves.

#3: Irritation to Fabrics or Laundry Detergents

An often overlooked cause of runner’s itch is skin irritation due to the fabrics or materials of your workout clothing and/or fragrances, chemicals, dyes, or other compounds in your laundry detergent.

If you have sensitive skin, these irritants can become heightened when you start sweating.

This means that although you might not be scratching your skin when you are running, once you start sweating during a workout, your sensitive skin will start reacting more noticeably to the irritants with your running clothes.

Choosing moisture-wicking running shorts and tights can help reduce the buildup of sweat.

Most of the best sweat-wicking materials for running are synthetic materials such as polyester, but certain natural fibers such as bamboo and merino wool can also be sweat-wicking and good for sensitive skin.

However, cheap wool running tights or base layers can cause very itchy legs while running because wool can be irritating if you don’t get high-quality, soft, brushed merino wool.

Make sure to wash all of your running clothes before you wear them for the first time.

If you use body soap or other body care products that have alcohol or other irritating ingredients, when your skin and sweat start interacting and your pores open up when you run, you might experience prominent itchiness on your legs, stomach, back, or even your arms.

A patch of dry, flaky skin.

#4: Dry Skin

Dry skin can also cause an itchy sensation when you are running. 

When body heat gets trapped under your running tights or running clothes, the dry skin can start to flake and itch, especially if you are not wearing moisture-wicking fabrics.

Consider using an all-natural moisturizer after your shower or even before you run.

#5: Exercise-Induced Vasculitis

Exercise-induced vasculitis can occur when you do some type of physical activity coupled with exposure to sunlight on a hot day.

For this reason, exercise-induced vasculitis is also known as golfer’s vasculitis, hiker’s rash, or even Disney rash.

#6: Exercise-induced Urticaria or Cholinergic Urticaria

In the absence of the aforementioned issues, the most common cause of itchy legs while running is due to a condition known as exercise-induced urticaria due to cholinergic urticaria.

Urticaria is the medical term for hives.2nadolpho. (2018). Hives. ACAAI Patient. https://acaai.org/allergies/allergic-conditions/skin-allergy/hives/

‌According to the Cleveland Clinic, cholinergic urticaria is a condition where you get hives and itchy when your body temperature increases, such as when exercising (especially in the heat) or taking a hot shower.3Cholinergic Urticaria. (n.d.). Cleveland Clinic. Retrieved February 13, 2024, from https://my.clevelandclinic.org/health/diseases/cholinergic-urticaria

A person running.

#7: Exercise-Induced Anaphylaxis

Exercise-induced anaphylaxis is essentially an allergic response to exercise—that’s right: apparently, it’s possible to be allergic to running!4Exercise-Induced Anaphylaxis: Practice Essentials, Background, Pathophysiology. (2023). EMedicine. https://emedicine.medscape.com/article/886641-overview?form=fpf

‌Exercise-induced anaphylaxis symptoms expand beyond just an itchy sensation in the legs while running, and can include hives, redness, swelling of the tongue or other parts of the body, headache, stomach cramps, and even difficulty breathing.

Healthcare professionals say that symptoms of exercise-induced anaphylaxis tend to be worse during high-intensity running (such as sprinting) or when running in hot weather or cold weather.

This condition can also occur during other types of physical activity such as hiking, cycling, or HIIT workouts.

#8: Underlying Conditions

Other possible causes of runner’s itch include food allergies, a side effect of certain medications, seasonal allergies, or other allergic reactions to something near where you are running or that you interact with shortly before your workout.


How To Treat Runner’s Itch

Runner’s itch tends to subside after several workouts if you are just getting started on your running routine.

Similarly, if you have seasonal allergies or have just started running outside in the summer, leg itchiness while running should start to go away as you acclimatize to the warmer weather or the pollen count decreases.

It can also be helpful to keep a journal about what you are eating, what you are wearing to run, any laundry detergent you are using, etc., and see if you can identify an allergy trigger.

Over-the-counter antihistamines such as Benadryl can be helpful in cases where the itchy sensation is severe or accompanied by hives, swelling, or other symptoms of an allergic reaction. 

If you are having difficulty breathing, you should call 911 and seek immediate medical attention.

There are also Benadryl sprays that can help with hives and mild allergic reactions. 

A runner with compression socks on.

A cooling shower, warm bath, aloe vera gel, hydrocortisone cream, calamine lotion, and a cold compress can also be helpful to soothe runner’s itch symptoms in affected areas, depending on the cause of your itchiness.

Some healthcare providers also suggest soaking in an oatmeal bath or Epsom salt bath.

Additionally, massage, foam rolling, muscle scraping techniques, and wearing compression stockings or tights to aid circulation and calm down irritated nerves may help relieve the itchy feeling.

You can try implementing these modalities before running to hopefully prevent runner’s itch symptoms or at least attenuate the itchy sensation when running.

If you are still experiencing symptoms of runner’s itch, or have concerns about an underlying condition or allergic response, you should speak with your healthcare provider.

For more tips and tricks for running in the heat, check out this next guide:


Photo of author
Amber Sayer is a Fitness, Nutrition, and Wellness Writer and Editor, as well as a NASM-Certified Nutrition Coach and UESCA-certified running, endurance nutrition, and triathlon coach. She holds two Masters Degrees—one in Exercise Science and one in Prosthetics and Orthotics. As a Certified Personal Trainer and running coach for 12 years, Amber enjoys staying active and helping others do so as well. In her free time, she likes running, cycling, cooking, and tackling any type of puzzle.

5 thoughts on “The Runner’s Itch Is Real: Here’s What Causes It (+ How To Treat It)”

  1. Thank you so much for this article. I use to be an avid runner and when I stated running again, I broke into painful hives. I have zero allergic reaction history.

    This makes so much sense. I will keep at it and start slow. Thank you, thank you!

  2. I found the best solution for runners itch. From what I understand it also is or could be an allergic reaction to the increase amount of oxygen flowing in your capillaries. The itching is a result of the histamine response that your body puts out in response to the oxygen. So all you need to do is take a small dose of anti-histamine about 15 minutes before you run/cadio. This will get rid of the itch and allow you to continue running/powering through your workout. After a while when you’ve been consistent you can eliminate taking the anti-histamine. My anti-histamine of choice is liquid children’s Claritin.


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