Pain is related to Severe. Severe is the opposite of Mild. Mild is the opposite of Extreme. 
Comparable is a synonym of Similar. Similar is related to Common. Common is related to Land. 
Pain <--RelatedTo--> Severe <--Antonym--> Mild <--Antonym--> Extreme 
Comparable <--Synonym--> Similar <--RelatedTo--> Common <--RelatedTo--> Land 