Lack of the thyroid hormone is referred to as hypothyroidism. If your pituitary is not producing one or more of its hormones, or not producing enough, then this condition is known as hypopituitarism. If you have a pituitary tumour, it may cause pituitary underactivity by the direct pressure of the tumour mass on the normal pituitary, or by the effects of surgical or X-ray treatment which you have undergone to treat the tumour. Again, fatigue is a common symptom, as is a general feeling of loss of physical well-being and vigour. You may also feel dizzy.
Some patients also suffer from nausea and diarrhoea.
You will need to attend a specialist clinic as a day patient for tests referred to as 'dynamic'. This means that you will have a blood test initially and then several more after you have been given something to stimulate the hormone. Most clinics either use an artificial version of the ACTH hormone or a test which reduces your blood sugar level. The test will show you how your hormone level reacts over a period of time. Treatment is by taking the adrenal hormone, cortisol.