Woman sweating at the gym

Sweat Rash: Causes, Symptoms And Treatments

If you’re hitting the gym more regularly, or sweating more often, you may have experienced a sweat rash, also known as heat rash or prickly heat. Known medically as miliaria crystallina or miliaria rubra, this common condition can cause some discomfort.¹ In this article, we'll explore the causes, symptoms and treatments for sweat rash and offer practical ways to prevent it.

What is a sweat rash?

A sweat rash is a specific type of skin rash that develops when you sweat a lot or are in a hot place, and your sweat ducts get blocked. When these sweat ducts are blocked, it can lead to a rash — small sweat-filled blisters under your skin.¹
A sweat rash can affect anyone. But people living in warm and humid climates and athletes are at higher risk. In fact, it affects up to 30% of adults² living in hot and humid conditions.

However, sweat rashes are common and usually go away on their own after a day to three days², but in severe cases (if it persists for a couple of weeks), it may require medical assistance.

Experiencing more sweat than usual? Check out our guide on effective sweating management strategies here.

Young athlete girl putting earphones on


There are many causes of a sweat rash, ranging from hot and humid conditions to fabric choices for your clothing. Let's explore 5 of the most common causes.¹,²

1. Hot and humid weather

When the weather cranks up the heat and humidity, your body's natural response is to start sweating. But if there's too much sweat being produced, your sweat ducts might feel a bit overwhelmed, leading to blockages.

2. Intense exercise or physical activity

We love releasing happy hormones through frequent intense workouts. While they’re fantastic for fitness, they can also be the starting point for sweat rashes.

3. Body hugging clothes

Tight-fitting clothes, especially those made from synthetic fibers don’t allow enough airflow between your clothes and your skin, creating a comfy spot for a potential sweat rash.

4. You’re prone to heavy sweating

If you have a condition that causes excessive sweating, you may be more prone to develop a sweat rash.

Explore the signs and symptoms of excessive sweating in our informative guide.

5. Taking medications that cause sweating

If you are taking any medicines that can cause you to sweat a lot, you could also develop a sweat rash. This can include some blood pressure medications, acne medications, or hormone therapies. If you’d like to find out more about these medications, read our article about them.

Recognizing the signs of a sweat rash

If you’re wondering if you have a sweat rash, look out for:²

1. Red bumps or tiny blisters on the skin

Small red bumps or tiny blisters might pop up, and they can be itchy.

2. Prickling sensation

Your skin might feel a bit prickly or tingly, especially where you sweat or where the rash is.

3. Itching and discomfort

You might feel itchy, and the affected area can be uncomfortable.

4. Swelling

The skin could turn red and a bit swollen, especially in the area of the rash.

6. Rash clusters or patches

The rash might show up in groups or patches, along the paths where you sweat.

3 types of sweat rash

Not all sweat rashes are alike. There are three main types you should be aware of:¹

1. Miliaria crystallina

It’s the mildest type with small, clear bumps filled with fluid on the skin's surface. These bumps are fragile and can easily break.

2. Miliaria rubra (prickly heat)

It causes an itchy or prickly feeling along with small, inflamed bumps on the skin. If the bumps fill with pus, it's called miliaria pustulosa.

3. Miliaria Profunda

It affects the skin's deepest layer, featuring firm and either painful or itchy bumps.

A woman in the shower

How to treat and prevent sweat rash

While sweat rashes usually clear up on their own, there are some things that you can try to help ease the rash or prevent future sweat rashes. Below, we share some helpful tips.

What shouldn’t I use to treat a heat rash?

You don’t want to clog your pores more when you have a sweat rash. Avoid lotions that have petroleum or mineral oils. Also, don’t use anything scented, and do not use baby powder.²

How do you get rid of sweat rash fast?

To help treat your rash at home, there are some things you can do at home, if it is a mild sweat rash:¹,²

  1. Wear loose-fitting clothing to prevent friction and further irritation.
  2. Wear breathable clothes made from natural fibers like cotton and linen to not trap sweat.
  3. If you’re suffering from night sweats, refrain from sleeping with too many blankets or warm PJs on. This can also trigger a sweat rash.
  4. Take cool showers to help cool down your skin and pat dry with a towel, especially in hot weather.

You could also try the following:

  1. Times of stress can cause you to sweat more. Destressing can prevent sweat rash by addressing the root cause of excessive sweating during stressful times. Read our tips for managing stress sweat here.
  2. If you're sweating too much, you could also consider switching up your deodorant or antiperspirant. Our recommendation? Degree’s Clinical Protection range of antiperspirant deodorants that offer prescription-strength wetness protection.


For women: Degree® Stress Control Clinical Antiperspirant Deodorant
For men: Degree® Clean Clinical Antiperspirant Deodorant

Learn how to sweat less from avoiding sweat-inducing foods to using the right products. Read more in this handy guide.

When to see a doctor about your rash

Sweat rashes can be uncomfortable, but with the right knowledge and treatment, you can manage and prevent them effectively. If your sweat rash persists for more than 3 or 4 days, appears to be worsening or if you’re in pain, you should consult your doctor.


  1. Guerra KC, Toncar A, Krishnamurthy K. Miliaria. StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing. Updated 2023Opens in a new window
  2. Heat Rash/Prickly Heat. Cleveland Clinic. Updated 2022.Opens in a new window