Today’s Subject: Hypothyroidism

Anyone who has had thyroid issues can tell you that it is not fun! Hypothyroidism is a disorder which, like Polycystic Ovaries and Endometriosis, is becoming more and more prevalent in the first world.  It is a pretty serious issue and I think everyone should at least be aware of the disorder. If thyroid disorders are untreated health can deteriorate and death would be inevitable. So I thought I better put something together for you all.

Image: www.nlm.nih.gov
Image: http://www.nlm.nih.gov

Hypothyroidism sometimes referred to as hypothyreosis, is the most common thyroid disorder with around 6 to 10% of the female population suffering from the condition (Melmed et al 2011). The condition is more prevalent with age with over a quarter of females aged over 65 year’s possible sufferers.
Hypothyroidism is an endocrine disorder which effects the thyroid gland and for whatever reason does not produce enough thyroid hormone. Thyroid hormone is responsible for the regulation of many metabolic processes including growth, development and energy expenditure.
Hypothyroidism can be classed as either primary or secondary (central). Primary hypothyroidism is where the thyroid gland suffers permanent loss or destruction or is diseased usually as a result of an autoimmune destruction, or an irradiation injury. Secondary or central hypothyroidism is caused by insufficient stimulation and is usually associated with a defect in the thyroid- stimulating hormone (TSH) molecule, or as a result of a hypothalamic or a pituitary disease.

The most common cause of hypothyroidism is Hashimoto’s disease. Hashimoto’s disease is an autoimmune disease where a variety of cell and antibody mediated immune responses attack the thyroid gland. It is a serious disease and if left untreated can cause death within 10 to 15 years (Melmed et al 2011). A genetic predisposition is a risk factor in developing hypothyroidism and evidence show that your risk of developing the condition is increased if you have an immediate family member who suffers with the condition (Chakera et al 2012).
Medical procedures is also a common cause of hypothyroidism. When cancer of the thyroid gland is removed a vast majority of the thyroid is taken with it. If too much is taken then the thyroid gland cannot produce enough thyroid hormone (TH) and hypothyroidism results. If a person suffers from hyperthyroidism then part of the thyroid can be removed or medication can be administered in order to suppress the action of the thyroid gland, which can lead to hyperthyroidism.
Iodine deficiency is also a causative factor with hypothyroidism. If there is a lack of sufficient iodine in the diet this can prevent the thyroid gland from making adequate amounts of TH. The thyroid tends to enlarge in an attempt to comply with the pituitary glands messages to produce more of the hormone. This is known as goitre.
If there is a dysfunctional pituitary gland or hypothalamus this can cause hypothyroidism. Pituitary gland dysfunction occurs when the pituitary gland does not make adequate amounts of TSH which promotes the thyroid gland to produce triiodothyronine (T3) and thyroxine (T4). Hypothalamic dysfunction is when there are issues with the thyrotropin- releasing hormone (TRH), this effects the function of the pituitary gland, which in turn effects the thyroid gland, and can cause hypothyroidism.

Image: http://www.endocrineweb.com/thyfunction.html
Image: http://www.endocrineweb.com/thyfunction.html

The thyroid gland is the only basis of TH that the body has. It requires the amino acid tyrosine, as well as iodine. The Iodine in the blood is absorbed by the thyroid gland and is turned into thyroglobulin molecules. This is a process is controlled by the pituitary gland which secretes TSH, if there are inadequate amounts of TSH or iodine then this causes a decrease in thyroid hormones.
The thyroid gland produces thyroxine (T4) which is converted into triiodothyronine (T3) by a selenium- dependant enzyme called iodothyronine deiodinase. Triiodothyronine bind to thyroid hormone receptors in cell nucleuses where it stimulates certain genes and produces certain proteins. Triiodothyronine also binds to the cell membrane which stimulates the sodium- hydrogen antiporter and such processes like formation of the blood vessels and cellular growth.
The maintenance of thyroid hormone levels is controlled by the hypothalamic- pituitary- thyroid axis. The production of TSH is by the anterior pituitary gland and is stimulated by TRH which is released form the hypothalamus. A negative feedback process lead by thyroxine decreases TSH and TRH. Lack of TRH leads to a lack of TSH, and as a result not enough TH, which leads to hypothyroidism.

It is highly uncommon for sufferers of hypothyroidism to be asymptomatic or have very mild symptoms. The disease manifests in a variety of ways, the most common being fatigue, as well as an increased sensitivity to cold, dry and flaky skin, swelling in the face particularly around the eyes, hoarseness or raspy voice, weakness in muscle control, muscle aches, stiffness and tenderness, joint pain, swelling or stiffness, elevated blood cholesterol levels, irregular menstrual bleeding, hair thinning, decrease and slowed heart rate, impaired memory, and depression.
If hypothyroidism goes untreated then symptoms can manifest to become quite severe. If the pituitary gland is constantly stimulating the thyroid to produce hormones, then the thyroid gland can become enlarged in order to try and cope with the demands.
If hypothyroidism advances it becomes myxedema, which is a rear and extremely severe form of hypothyroidism. This can be life- threatening and manifest in the form of low blood pressure, decreased body temperature, decreased breathing, and can lead to unresponsiveness and even coma, which can be fatal.

Hypothyroidism or hypothyreosis is an endocrine disorder which has an effect on the thyroid gland. Due to various reasons the thyroid gland fails to produce thyroid hormone, which is needed in many metabolic processes such as the formation of blood vessels, energy expenditure, as well as cellular growth and development.
It is the most common disorder of the thyroid and effects around 6 to 10% of the female population, with those over 65 years being the main sufferers.
Hypothyroidism generally has two classifications, primary and central or secondary. Primary being when the thyroid suffers permanent loss or is diseased as a result of an autoimmune destruction or an irradiation injury. Secondary or central is caused by insufficient stimulation and is usually associated with a defect in the thyroid- stimulating hormone molecule, or as a result of a hypothalamic or a pituitary disease. Secondary hypothyroidism can be managed and even reversed if there is a correct treatment management plan in place.

Aly Curd

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2 Comments Add yours

  1. Sue Biggar says:

    Aly, what can be done to prevent it?

    Like

    1. alycurd says:

      Hi Sue. Due to its congenital natural it makes prevention difficult but by understanding the risk factors, recognising symptoms and getting an early diagnosis can prevent serious complications from the disease.

      Like

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