Module 6 — The SUDS scale | ERP Course
- Jun 5
- 5 min read
Updated: Jun 7
Free Course by Everything IFS Academy | Therapeutic Modalities Series
Module 6 — The SUDS Scale
Every skilled practice needs a way to measure what it is working with, and ERP's is refreshingly simple: a single number. It is not a clinical instrument that requires training to use, and it is not precise in the way a thermometer is precise. It is a quick, personal read on how much distress is present in a given moment. This is a short lesson on purpose, because the tool itself is small. But it is used constantly throughout ERP, so it is worth understanding clearly. This lesson covers what the number is, how to make it meaningful, and how to read it well.
What SUDS Is
SUDS stands for the Subjective Units of Distress Scale. It is a self-rating of how much distress a person feels, usually placed on a scale from 0 to 100, though some people prefer a simpler 0 to 10. A 0 means complete calm, no distress at all. A 100 means the most intense distress a person can imagine, full-blown panic or dread. Everything else falls somewhere in between.
The scale was introduced in the 1960s by the psychologist Joseph Wolpe, working with Arnold Lazarus, and it has been a basic instrument of exposure work ever since. The first word in its name is the most important one. It is subjective. SUDS does not claim to measure distress objectively from the outside. It captures the person's own felt sense of it from the inside, which is exactly what makes it useful for the kind of inner experience ERP works with.
Anchoring the Scale to One Person
A bare number means little until it is anchored. The genuine skill in using SUDS is defining what the numbers actually feel like for the specific person using them, because there is no universal yardstick that fits everyone.
In practice this means giving the scale personal landmarks. A low number, somewhere around 20, might be a faint flicker of unease, a slight tightening that is easy to carry on through. A middle number, around 50, might be a clear knot of anxiety, a quickened pulse, a discomfort that is hard to ignore but still manageable. A high number, an 80 or 90, might be a pounding chest, racing thoughts, and a powerful urge to escape. The particular sensations differ from person to person, which is the point. Once a person has described what their own 30, 50, and 80 feel like, the scale stops being abstract and becomes a reliable personal gauge they can return to.
Because the scale is anchored this way, the numbers only mean something within one person. One person's 60 might be another's 30, or their 85, so there is nothing to gain by comparing a rating to anyone else's, and doing so can quietly mislead, since it measures against a yardstick that was never theirs. The only comparison that carries information is to one's own earlier readings, which is what reveals movement over time.
And if numbers themselves feel clinical or hard to summon, they are not required. The same anchoring works just as well with plain ranges, low, medium, and high, or with colors, or with a few words that capture the feeling. What makes the scale work is that it tracks relative change, whether one moment is more or less intense than another, not the exactness of any figure, and it gets easier as the inner landmarks grow familiar.
Why the Number Moves Around
One feature of SUDS surprises people at first: the same trigger can earn very different ratings on different days. A situation that registers as a 40 on a rested, settled morning might climb to a 70 after a bad night's sleep, a stressful week, or simply at a low point in the day. This is not a flaw in the scale, and it does not mean a rating was wrong.
Distress genuinely fluctuates with sleep, mood, hunger, stress, and a dozen other ordinary factors, and SUDS faithfully reflects that. The shifting number is information, not error. It shows how much the surrounding conditions of a day shape how a trigger lands. There is no need to chase a single "correct" rating for any situation. An honest, in-the-moment read, even a rough one, is exactly what the tool is for.
Tracking Distress in Real Time
Beyond rating a situation in advance, SUDS becomes a way to watch distress unfold as it happens. When a person stays in contact with something that provokes anxiety, the distress tends to follow a recognizable shape over time. It often climbs, sometimes quite sharply at first, then levels off into a plateau, and then, given time, begins to ease.
Checking in on the number periodically, at the start, partway through, and afterward, turns a single snapshot into a moving picture. It lets a person notice the arc rather than just the peak: that the spike came and held and then softened, that the rise was steep but the fall was real. This moving read is part of how the experience gets understood. It is worth stressing, though, that this curve is something observed, not something forced, which leads to the most important point about the whole tool.
A Gauge, Not a Goal
It would be easy to assume that the aim of ERP is to get the number down, to drive the SUDS toward zero and call that success. It is not, and treating it that way quietly misses the point.
SUDS is a gauge. Like the speedometer in a car, it tells a person where they are; it is not the destination, and staring at it does not move the car. The reason this matters is rooted in how exposure actually works, which is that the purpose of facing a fear is to learn something, not to lower a reading. A number that stays high while a person discovers they could handle the situation has done its job perfectly well. So SUDS is used to understand, to calibrate, and to notice patterns over time, never as a scoreboard to be beaten. Reading the gauge is helpful. Chasing it is not.
The same balance carries over to everyday life, where SUDS can be a handy gauge well beyond formal practice: a quick way to name what is being felt, notice what tends to spike it, and catch avoidance creeping in. The one caution is that taking the reading too often can itself harden into a checking ritual, an anxious habit of taking one's own temperature every few minutes. Used lightly, it builds awareness; used compulsively, it becomes one more thing to watch. The aim is awareness, not surveillance.
Below this lesson, you'll find an ERP exercise along with a few ways to begin noticing and practicing it in everyday life this week.
Disclaimer: Everything IFS Academy is an independent educational platform and is not affiliated with, endorsed by, or connected to the IFS Institute. While we strive for accuracy, errors can occur, and users are encouraged to cross-reference critical information. These courses, lessons, skills, and practices are offered for educational and self-reflection purposes only. They do not constitute therapy, mental health treatment, clinical training, or crisis support, and they should not be used as a substitute for professional mental health care.
Crisis Support: 🚨 If you are experiencing a mental health crisis, feel unsafe, feel at risk of harming yourself or someone else, or feel too overwhelmed to safely use self-directed practices, please pause this material and reach out for immediate support. Contact a licensed mental health professional, call or text 988 in the U.S. or Canada, or use your local emergency or crisis resources.
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