Linked from
The 41 pages that link to Pain, each with the reason it gives.
SensationRelated: Nociceptive detection contributes to pain, though the two are not identical.
Vasovagal syncopeRelated: Sudden pain is a recognized trigger for reflex fainting.
Vital signsRelated: Pain is sometimes called the fifth vital sign, though it is subjective.
SadismRelated: Pain is one possible source of the distress or sensation involved in sadism.
EndorphinsRelated: Endorphin effects on pain differ across individuals, settings, and types of pain.
CryingRelated: Physical pain can trigger crying even without sadness.