Hide and Unhide Rows by clicking a cell.

Hi,
Welcome to the forum.

Try this to see if this works for you.

Private Sub Worksheet_SelectionChange(ByVal Target As Range)
Dim i As Long
Application.ScreenUpdating = False
Application.EnableEvents = False
     If Target.Count > 1 Then Exit Sub
     If Not Intersect(Target, Range("C8,C14,C19,C29,C39,C48,C55")) Is Nothing Then
         i = Target.End(xlDown).Row - 1
         If Range(Cells(Target.Row + 1, Target.Column), Cells(i, Target.Column)).EntireRow.Hidden = False Then
            Range(Cells(Target.Row + 1, Target.Column), Cells(i, Target.Column)).EntireRow.Hidden = True
            Target.Offset(-1, 0).Select
         Else
            Range(Cells(Target.Row + 1, Target.Column), Cells(i, Target.Column)).EntireRow.Hidden = False
            Target.Offset(-1, 0).Select
         End If
     End If
Application.EnableEvents = True
Application.ScreenUpdating = True
End Sub

Insert one more blank line before each header and this should work fine. I have changed the code accordingly.