How much pain is acceptable?

Although there's a pain scale, interpreting pain levels on a 0-10 scale, where 0 is no pain, and 10 the worst pain possible, pain acceptability depends on an individual's subjective assessment of whether their current level of pain is something they can live with while maintaining a certain quality of life and functioning.

In other words, pain acceptability depends on pain tolerance, which is the maximum level or duration of pain an individual is able to withstand. Pain tolerance is a measure of a physiological and psychological limit.

Therefore, since pain tolerance varies between people due to a complex mix of biological, psychological, and social factors, including genetics, age, lifestyle, emotional state, and cultural background, which influence how sensitive an individual is to pain and how much pain they can handle, there's no conventional level of acceptable pain that's applicable to all people.

People sweat for many different reasons. While the primary function is to regulate body temperature and prevent overheating, sweating is also a response to emotional, physical and medical triggers, and pain, which can make people sweat because it triggers the body's stress response, leading to emotional sweating. 

Pain is a physical stressor that can activate the sympathetic nervous system, which controls the body's fight-or-flight response, including sweat glands.  

Of course, it's normal that one sweats when they're in pain, depending on the intensity of their pain and the degree of their pain tolerance.

How, exactly are we supposed to rate pain ?

I am in constant pain from my shoulders (arthritis and bicep tendonitis) which I rate as level 9 - ramping up to 20 when my shoulders lock and I move my arms even a tiny amount in any direction.. These are out of 10

Some people can take pain - I can't