Pain intensity was graded into'slight','moderate','severe', or'agonizing'degrees (Grades 1, 2, 3 and 4 in Table 1). It was found that though there was no difference between those describing their pain as' slight'and those describing it as' moderate', there was a significant statistical difference between these two groups and those classifying their pain as' severe'or'agonizing'. The intensity of pain was clearly shown to be inversely related to the pressure pain threshold, ie the higher the pain threshold the less intense the pain (Table 1). Similarly, inverse relationship was demonstrated to exist between the pain threshold and the duration of the pain (Table 2); that is to say the higher the patient's threshold the shorter was his pain with cardiac infarction. There was also a significant inverse relationship between the pain thresholds