Pain Intensity Categories
The definitions on this page are central to the Cumulative Pain method, a core component of the Welfare Footprint Framework. They provide the standardized criteria used to classify the intensity of affective experiences across time—making it possible to measure suffering in a scientifically grounded, transparent, and comparable way.
In this Welfare Footprint method, ‘Pain’ is defined as a shorthand for any felt negative affective state — whether of physical origin (e.g., injury, hunger, heat stress) or psychological origin (e.g., fear, anxiety, frustration). The term is capitalized to distinguish this technical usage from the everyday sense of ‘pain.’
Intensity, when referred to in relation to Pain, denotes the subjective measure of unpleasantness or aversiveness experienced by an individual. This measure is not directly tied to the physical stimuli’s magnitude but rather to the personal, subjective experience of the Pain’s severity or distress.
Below, you will first find a brief summary of the Pain intensity categories along with the color codes used in our visual tools (such as the Pain-Track). Further down, we provide the full definitions, including behavioral, physiological, and functional descriptors that inform the classification of each level.
Annoying. Experiences of Pain perceived as aversive, but not intense enough to disrupt routine in a way that alters adaptive functioning or affects the behaviors that individuals are motivated to perform. Similarly, Annoying Pain should not deter individuals from enjoying pleasant experiences with no short-term function (e.g., play) and positive social interactions. Sufferers can ignore this sensation most of the time. Performance of cognitive tasks demanding attention are either not affected or only mildly affected. Physiological departures from expected baseline values are not expected to be present. Vocalizations and other overt expressions of Pain should not be observed.
Hurtful. Experiences of Pain in this category disrupt the ability of individuals to function optimally. Different from Annoying Pain, the ability to draw attention away from the sensation of Pain is reduced: awareness of Pain is likely to be present most of the time, interspersed by brief periods during which Pain can be ignored depending on the level of distraction provided by other activities. Individuals can still conduct routine activities that are important in the short-term (e.g. eating, foraging) and perform cognitively demanding tasks, but an impairment in their ability or motivation to do so is likely to be observed. Although individuals may still engage in behaviors they are strongly motivated to perform (i.e., exploratory, comfort, maintenance), their frequency or duration is likely to be reduced. Engagement in positive activities with no immediate benefits is not expected. Reduced alertness and inattention to ongoing stimuli may be present. The effect of (effective) drugs (e.g., analgesics if the Pain is physical, psychotropic drugs in the case of psychological Pain) in the alleviation of symptoms is expected.
Disabling. Pain at this level takes priority over most bids for behavioral execution and prevents most forms of enjoyment or positive welfare. Pain is continuously distressing. Individuals affected by harms in this category often change their activity levels drastically (the degree of disruption in the ability of an organism to function optimally should not be confused with the overt expression of Pain behaviors, which is less likely in prey species). Inattention and unresponsiveness to milder forms of Pain or other ongoing stimuli and surroundings is likely to be observed. Relief often requires higher drug dosages or more powerful drugs. The term Disabling refers to the disability caused by Pain, not to any structural disability.
Excruciating. All conditions and events associated with extreme levels of Pain that are not normally tolerated even if only for a few seconds. In humans, it would mark the threshold of Pain under which many people choose to take their lives rather than endure the Pain. This is the case, for example, of scalding and severe burning events. Behavioral patterns associated with experiences in this category may include loud screaming, involuntary shaking, extreme muscle tension, or extreme restlessness. Another criterion is the manifestation of behaviors that individuals would strongly refrain from displaying under normal circumstances, as they threaten body integrity (e.g. running into hazardous areas or exposing oneself to sources of danger, such as predators, as a result of Pain or of attempts to alleviate it). The attribution of conditions to this level must therefore be done cautiously. Concealment of Pain is not possible.
Summary definition and expected observations in four categories of intensity of Pain.
Annoying | Hurtful | Disabling | Excruciating | |
|---|---|---|---|---|
Summary definition | Perceived only as a discomfort | Pain intensity that clouds focus but allows basic tasks | Pain that takes priority over most bids for behavioural execution | Extreme level of Pain felt unbearable |
Disruption of ability to conduct routine activities (1) | No | To some degree | Substantial | Complete |
Performance of motivated & positive behaviours | Not affected | Frequency and/or duration reduced | Not expected | Impossible |
Willingness to trade resources, work and safety (risk-taking) for Pain relief | Minimal | Moderate willingness to trade resources, risk-behaviour not affected | Willingness to trade important resources, work & safety to avoid Pain | Complete focus on eliminating Pain at all costs, including sacrifice of vital resources (eg life) |
Pain-specific manifestations (2) | Not expected | Not expected, particularly in prey | Likely | Extreme |
Attention to Pain: can Pain sensation be ignored? | Most of the time | For some time, depending on distraction | Very briefly, Pain is continuous | No |
Attention to surroundings | Not affected | Reduced to some degree | Substantially reduced | Attention is exclusive to Pain |
Cognitively demanding tasks | Individuals can focus, solve problems, and stay attentive; discomfort can be ignored most of the time | Tasks can still be done, but attention and motivation are reduced; performance drops, and the pain often intrudes on concentration. | Focus is continuously hijacked by pain; most higher-level cognitive processes and learning tasks are disrupted. | Cognitive functioning collapses; the mind is consumed by the experience of pain itself, leaving almost no room for attention to other tasks. |
Departures of neurophysiological parameters from baseline | No measurable | Mild departures | Marked departures | Extreme departures. |
Are Pain-relieving drugs effective? | No effect expected | Typical doses and drugs can eliminate the Pain | Only higher doses or more powerful drugs | anesthesia or unconsciousness may be required |
How long can Pain be tolerated? | Continuously | Continuously | Barerly, with major impairment of life quality | Can be willingly tolerated for only seconds |
For definitions of positive affective states used in the Cumulative Pleasure method, please refer to the corresponding page here.
