If you’re feeling stressed, overwhelmed or anxious, there’s a mental health tool that’s simple and free: screaming.

Emory University professor Harold Gouzoules, who holds a master’s in psychology and a PhD in zoology, has studied screams — from both humans and animals — for decades. He’s detected that screams convey six types of emotions: fear, pain, surprise, happiness, anger, and frustration or sadness.

Scream therapy was first introduced in the 1970s by celebrity therapist Dr. Arthur Janov. It’s also known as scream meditation and primal scream therapy. Janov argued that mental health issues stemming from repressed childhood trauma could be alleviated through guiding screaming sessions.

While scream therapy is not without its detractors, proponents say it can be useful for releasing built-up tension and emotion, removing mental blocks and increasing feelings of empowerment

Meditation expert Tristian Gribbin, founder of meditation site Flow demonstrated the technique during a TEDx Talk, asking the audience to scream into towels.

“Notice how after you scream, you feel lighter, better and ready to face your day. You will have more ease in your communications with others,” Gribbin said.

If you’d like to try some unguided scream meditation on your own, here are a few tips:

  • Find a space that brings you comfort and where you can be alone.
  • Grab a towel, pillow, or blanket — anything that can help muffle sound.
  • Take a few deep breaths, and on the last breath, release and scream.

Beyond the meditative benefits, studies have shown that screaming promotes maximal muscular power during exercise.