High levels of cortisol may mean you have Cushing's syndrome, while low levels may mean you have Addison disease or another type of adrenal disease. If your cortisol results are not normal, it doesn't necessarily mean you have a medical condition needing treatment. Other factors, including infection, stress, and pregnancy can affect your results. Birth control pills and other medicines can also affect your cortisol levels. To learn what your results mean, talk to your health care provider.