Dr Mary McCarthy: Talk for group focussed on wider issues

The Shrewsbury group are a very active division, meeting once a month and covering a wide variety of themes. Amongst the many services on offer are educational evenings, Christmas dinners, and summer walks all underpinned by the well organised secretary, chair and a team of enthusiastic helpers. Rather than speaking strictly about diabetes, I was asked to explore beyond the parameters of this topic.

Diabetes is part of a group of hormone diseases caused by disruption to the endocrine system. I decided therefore to do my talk on endocrine diseases and their various forms. Thyroid problems come under this category, involving both under-action and over-action of the thyroid gland, as well as diseases of the adrenal glands which sit on top of the kidneys and the pituitary gland, such as Addison's disease.

The pituitary is a small gland sitting at the base of the brain; roughly level, though further back, with the bridge of the nose. You can imagine the pituitary gland as the conductor of the endocrine orchestra given that it influences and moderates the effects of other glands. It produces a thyroid stimulating hormone, which encourages the thyroid gland to push out thyroxine.

Thyroxine is a bit like the accelerator on a car – it determines how fast your body works. Too much thyroxine makes you jittery and nervous; your heart will race and you may find it difficult to sleep. You lose weight and, if you're a women, periods are disrupted. Too little thyroid hormone and you put on weight, your body slows down and not only do you sleep easily but you feel permanently tired. Your hair falls out and your skin thickens. Luckily, both overactive and underactive thyroids can be managed by either medical or surgical treatment. Another hormone produced by the pituitary is the human growth hormone and over production of this in childhood can lead to humans developing well beyond average in what is known as pituitary gigantism.

Normal levels of growth hormone production will mean that people stop growing as the ends of their long bones fuse. With gigantism however, the over activity of the pituitary gland means that this natural limit will not apply. This can also have serious health implications, particularly in pressure that is placed on organs.

Thankfully, what was once a cause for medical curiosity can know be explained as a disorder of the pituitary gland.