I need to create a matrix that keeps count of varying categories.

[Nimrah]

I have a list of patients with demographic characteristics. 

Here's an example:

Patient	ID	DOB	Gender	Ethnicity	Race	MRN	Diagnosis
Doe, Jane	001	01/01/91	F	Non-Hispanic	White	12345678	CD
Smith, John	002	02/02/92	M	Non-Hispanic	Black or African American	0246810	UC
Knobi, Obi Wan	003	03/03/93	M	Non-Hispanic	Asian	36912151	UC

I want to create a matrix that will show me the number of patients that meet two different categories, like for example, I want one of the cells in the matrix to show me how many patients are Female (F) and also Non-Hispanic. How would I do this?

[#2]

have you considered pivot tables ? 

You can find the options to create pivot table under menu "Insert->Pivot table"  

it will look like picture attached.  once you create a pivot table , you can drag the different field to rows/columns 

[#3]

@Nimrah 

Power Pivot is more flexible solution, however alternatively you may use COUNTIFS to count number of patients using criteria.