The pain scale is a subjective measure given by the patient.

Three factors determine the objective severity of pain. Measuring objective pain is a methodological question that occupies many patients,

The pain scale is a subjective measure in which the person is asked about the pain level. The objective measurement of pain tries to quantify the pain objectively. Primarily to assess the pain level of injuries and chronic patients witnessing. To this day, to the best of my knowledge, there is no objective measure of pain. The subjective perception of pests has a relatively high variance.

1. The Density of the sensory nerves (nociceptors) differs in different body areas. The head area, palms, hands, genitals, and nipples are rich in sensory nerves, which tend to hurt more.
   • Essential organs are not pain-sensitive, such as the brain and the liver. 
2. Cumulative tissue damage = The multiplication of the affected tissue damage volume multiplied by the duration of exposure to the harmful agent.
   1. The intensity of tissue damage volume. (Per time unit) 
   2. Duration of exposure to the harmful agent.
3. The Regeneration rate of the damaged tissue is directly proportional to the speed at which the pain passes. For example, skin cells recover quickly, so the pain passes relatively quickly when we cut ourselves superficially with a knife. 

It is possible (but challenging) to produce a statistical estimate of objective pain. Still, the patient's subjective response to pain is often more important than the intensity of the objective pain!

Continue reading: Subjective pain scale and determining the objective pain level.