You may be able to prevent and treat breakouts due to sweat by gently washing the area and using acne medication. Other health conditions, like a heat rash, can look like sweat pimples.

If you find yourself breaking out after a particularly sweaty workout, rest assured it’s not unusual. Sweating — whether from hot weather or exercise — may contribute to a specific type of acne breakout commonly referred to as sweat pimples.

The combination of sweat, heat, and friction can lead to clogging of pores. Plus, sweat on your skin may keep acne-causing bacteria in place.

Acne breakouts from sweat are more likely to appear when sweat combines with pressure or friction from headbands, hats, clothing, or backpack straps. Medically speaking, this is known as acne mechanica.

Keep reading to learn how to treat and prevent sweat pimples, and how to tell the difference between sweat pimples and bumps caused by heat rash.

Sweat pimples should be treated like any acne breakout:

  • Gently wash (not scrub) the area twice a day.
  • Use noncomedogenic, non-acnegenic, oil-free products.
  • Resist touching or picking.
  • Use acne medication.
  • Wash clothing, sheets, or pillowcases that touch your acne-prone skin.

To prevent acne breakouts due to sweating:

  • Maintain your regular acne treatment routine of washing and medication.
  • After periods of heavy sweating, shower with antibacterial soap.
  • Wash your workout clothing regularly.
  • Avoid tight-fitting clothes and accessories.
  • When possible, seek cooler areas with lower humidity, particularly during the hottest part of the day.
  • If possible, take special care to avoid tight clothing or equipment that may be contributing to the breakout (e.g. a chinstrap causing chin acne breakouts).

Another thing to consider is that the bumps on your skin may be a symptom of heat rash, rather than an acne breakout.

Heat rashes are caused by excessive sweating, typically during hot, humid weather. When blocked sweat ducts trap perspiration under your skin, the result is heat rash.

Heat rash symptoms can look like pimples

The two most common types of heat rash, miliaria crystallina and miliaria rubra, can look very similar to acne. In fact, experts at the University of Pittsburgh describes heat rash as looking like “a cluster of red bumps that resemble pimples.”

  • Miliaria crystallina (sudamina) can appear as small white or clear, fluid-filled bumps on your skin’s surface.
  • Miliaria rubra (prickly heat) can appear as red bumps on your skin.

Typically, miliaria crystallina is not painful or itchy, while miliaria rubra can cause prickly or itchy sensations.

Heat rashes typically appear on the back, chest, and neck.

The treatment for mild heat rash is to remove yourself from exposure to excessive heat. Your rash will most likely clear once your skin is cool.

If the rash is severe, your doctor may recommend topical treatments, such as:

To avoid heat rash, take steps before exposing yourself to situations that might result in heavy sweating. For example, don’t exercise outdoors during the hottest part of the day.

Or, in an especially hot, humid environment, try working out first thing in the morning, before the sun has had a chance to heat things up.

Additional suggestions include:

  • Wear soft, loose-fitting, lightweight cotton or moisture-wicking clothing when the weather is hot.
  • Seek shade or air-conditioning during hot weather.
  • When showering or bathing, use a soap that doesn’t dry your skin and cool water.
  • Allow your skin to air dry as opposed to using a towel.
  • Avoid using ointments that can block pores, such as those containing mineral oil or petroleum.
  • Make sure your sleeping area is well ventilated and cool.

Although excessive sweating can contribute to acne breakouts, your sweat pimples could also be a symptom of heat rash.

You might be able to address both conditions by cooling off and:

  • avoiding places and activities that increase sweating
  • washing — but not over-washing or scrubbing — your skin
  • using gentle antibacterial soaps and non-comedogenic products
  • cleaning your clothing, bedding, and other materials that come in contact with your skin
  • wearing loose-fitting, lightweight clothing when the weather is hot