'Increase' can be both a countable and uncountable noun. What is the best way to determine that? For example, is it "There is increase in blood pressure" or "There is an increase in blood pressure"? Dictionaries give many examples of 'increase' as a countable noun with the article 'an'. Can you explain when I can use 'increase' as an uncountable noun without an article or helper words (some, great deal of)?