after surgery. It is in Chapter 1 of every surgery textbook. When your body undergoes the stress of anesthesia, or the stress following a serious trauma or accident, there are specific hormonal shifts that occur. One very important hormone for mood and well being is a hormone called cortisol which is produced by the adrenal gland.When our body has a major stressful event, our adrenal glands squeeze every spare molecule of cortisol into the blood stream. Your body essentially prepares for battle. Blood insulin drops and blood sugar rises to feed the muscles.There are about a dozen other hormonal shifts like this as a result of stress. Since normal levels of cortisol makes us feel at ease or peaceful inside, extra cortisol can make us almost feel like we are on a high after surgery for a day or two.But all that goes up must come down. The adrenal glands cant replace the spent cortisol very rapidly. Therefore, around the third day post stress the blood cortisol level dips to very low levels which makes humans feel fatigue, depleted, and even sad. I have seen grown men cry on the third day post surgery. Fortunately, cortisol production catches up fairly rapidly so that often by the 4th or 5th day the "blues" are mostly history. It is a pattern that we always look for to reassure us as doctors that a patient is healing normally and is not at the beginning of a complication like infection or bleeding. In fact we used to look for what we call the "lipstick sign" on or about the 4th day, because if we noticed that on the 4th day that a patient was up and moving around, taking more interest in their appearance by applying a bit of makeup and brushing hair, we felt more assured that the patient was experiencing a normal post op course and complications were unlikely. Take all this information with the hope that you are feeling and behaving fairly normally especially taking into account all of the chemical and hormonal changes your body has gone through in the last week.I suspect you are just fine, but as always I recommend confirming this with your surgeon who can examine you to confirm that all is well. Take care and thank you for your question.