When you have kidney disease, your kidneys are no longer able to remove waste effectively from your body or to balance your fluids. The build up of wastes can change the chemistry of your body causing some symptoms that you can feel, and others that you don't.
Reference to a range of cells is typically of the form (A1:A6), which specifies all the cells in the range A1 through to A6. A formula such as =SUM(A1:A6) would add all the cells specified and put the result in the cell containing the formula itself.
Type in the function that you would like to calculate. You can select a cell or group of cells as variables. For example, to add the value in cell A1 to the value in cell A2, you can type in the function =A1 + A2. Press Enter on the keyboard when you are done and wish Excel to calculate the answer.