What causes it?

Your hypothalamus and pituitary gland stops working properly for a number of reasons:

  • when your brain was developing it didn't develop properly – the scan can show things like a very small pituitary gland, a very thin stalk between the pituitary gland and the hypothalamus, bits of the pituitary gland in the wrong place and problems with the nerves from your eyes
  • if you have a tumour (lump that's not supposed to be there) in or near your hypothalamus or pituitary gland – some of the names of tumours are astrocytoma, craniopharyngioma, germinoma, pituitary tumour
  • if you have been treated with radiation to your head for a tumour or leukaemia
  • if you hit your head really badly
  • sometimes we just don't know why and no reason can be found
As your hypothalamus and pituitary gland make lots of hormones if it is damaged you may not be able to make all of them. Sometimes it:

  • just affects one hormone (growth hormone is the most common one)
  • affects lots of hormones
  • rarely if you have a particular sort of pituitary tumour it can produce too many hormones

Questions you could ask your doctor or nurse

  • Can you tell what caused my hypothalamus and pituitary gland not to work properly?
  • Will my hormones get better with time or worse with time?