Returning value based on multiple criteria

Please could you kindly help, I am trying to get a column to return a number based on: 

IF

[High Potential?] = No and blank 

[Severity#] = 37

Return 7

AND

[High Potential?] = Yes

[Severity#] = 37

Return 3

AND

[Severity#] = any other numbers

Return [Severity#] value

Thank you very much