Dr Chinnadorai Rajeswaran, consultant endocrinologist explains about pituitary gland problems. Please email him, if you need more information.
Pituitary is a tiny gland situated in the head. It is located behind the bridge of the nose. It used to be known as the master gland. However, this master gland is controlled by the hypothalamus which is situated immediately above the pituitary gland.
Pituitary gland produces several hormones (Chemical which carry messages), which controls other glands like thyroid, ovaries, adrenals and testicles. Pituitary gland has a front part are anterior pituitary and the back or posterior part. Each of these parts produce different hormones.
Hormones produced by the anterior pituitary include:
- Adrenocorticotrophic hormone (ACTH)
- Thyroid-stimulating hormone (TSH)
- Luteinising hormone (LH)
- Follicle-stimulating hormone (FSH)
- Prolactin (PRL)
- Growth hormone (GH)
- Melanocyte-stimulating hormone (MSH)
Hormones secreted by the posterior pituitary include:
- Anti-Diuretic Hormone (ADH)
Each of these hormones control and regulate different glands and organs of the body. They are continuously monitored and the amount of hormones produced keeps changing depending on the need.
What problems are encountered with the Pituitary gland?
Problems encountered with the pituitary gland is based on:
- Excess production of hormones
- Decreased production of hormones
- Tumour of the pituitary
When there is an enlargement of the pituitary gland or if there is a tumour of the pituitary, either there can be increased secretion of hormones or decrease in hormone secretion.
Increase in size of the pituitary gland can also lead to pressure effect. Pituitary tumour can press on the nerves involved in vision and leads to visual field defect. Usually visual field defect noticed in people with large pituitary tumour is called bitemporal hemianopia. This means people notice that vision is missing in the outer half of both the right and left visual field.
What can happen when there is an increase or decrease of some of these hormones. Explained below:
ACTH: ACTH(Adrenocorticotrophic hormone) stimulates the adrenal gland to produce a hormone called cortisol. Excess ACTH results in a condition called Cushing’s disease. Decreased ACTH leads to secondary adrenal insufficiency.
TSH: TSH (Thyroid Stimulating Hormone) stimulates the thyroid gland to secrete thyroxine. Low TSH leads to secondary hypothyroidism.
LH and FSH: (Luteinising Hormone and Follicle Stimulating Hormone) Both of these hormones are collectively known as gonadotrophins. LH and FSH control reproductive functioning and sexual characteristics. They stimulate the ovaries to produce oestrogen and progesterone. In men they stimulate the testes to produce testosterone and sperm.
Prolactin: Prolactin stimulates the breasts to produce milk. Excess production of prolactin is usually seen in prolactinoma. Prolactinoma is a tumour of the pituitary gland. If the size of the tumour is less than a centimetre, it is called microprolactinoma. If the size of the prolactin producing tumour is more than a centimetre it is called macroprolactinoma.
Excess production of prolactin can lead to headache, irregular periods, infertility and excess milk production from the breast.
Normally this hormone is secreted in large amounts during pregnancy and breast feeding.
GH: Growth hormone or GH stimulates growth and repair. Excess growth hormone can lead to a condition called acromegaly. In this condition the person is tall and has classic features. People with acromegaly are prone to develop a number of medical conditions including type 2 diabetes, sleep apnoea etc.
ADH : The ADH (Anti-Diuretic Hormone) also called vasopressin controls the fluids and salts in the body. ADH controls how much water is retained by the kidney.
High levels of Anti-Diuretic Hormone (ADH) cause the kidneys to retain water in the body. This can lead to a condition called Syndrome of Inappropriate Anti-Diuretic Hormone secretion (SIADH) in which sodium levels in blood is low (hyponatraemia).
Low levels of Anti-Diuretic Hormone (ADH) will cause the kidneys to excrete too much water, leading to dehydration and drop in blood pressure. Low levels of anti-diuretic hormone cause a condition called Diabetes Insipidus (DI). DI usually results from a tumour, injury or inflammation of the pituitary gland or hypothalamus. Diabetes insipidus is associated with increased thirst and excessive urine production.
What are the common pituitary conditions seen in clinical practice?
There are a number of conditions which involves the pituitary gland, however some conditions are commonly seen in the clinic:
- Non-functioning pituitary adenoma
- Headache/visual disturbance due to large pituitary tumour
- Pituitary tumour leading to erectile dysfunction
- Cushing’s disease
What investigations are done in pituitary problems?
Investigations will depend on the symptoms and signs. Usually a battery of blood tests including pituitary hormone tests are done. This is followed by a stimulation or suppression test to confirm the actual defect. Pituitary MRI is thereafter done to locate the problem area.
What is the treatment?
Treatment for pituitary condition depends on the symptoms, signs and the outcome of investigations. Treatment includes medications and in some instances, pituitary surgery followed by radiotherapy. Regular follow up, blood tests and imaging are done at regular intervals.
Dr Chinnadorai Rajeswaran is a consultant Physician specialising in Endocrinology, Diabetes and Obesity. As a private endocrinologist he has private endocrine, diabetes and weight loss clinics in Harley Street, London, Chennai (India), Claremont Hospital, Sheffield, Nuffield Hospital, Leeds and Simplyweight, Bradford.
He has face to face consultations with people from Barnsley, Rotherham, Chesterfield, Doncaster, Wakefield, Huddersfield, Bradford, Harrogate, Leeds, Sheffield, London and Chennai (India). He also offers video consultations.