One of the most heard medical problems is the thyroid problem. So, what are the causes of thyroid problems?
Causes for thyroid problems can range from simple nutritional imbalance to very complicated factors that are intrinsically connected with the biological functioning of thyroid. Thus, before we go into the causes of problems, it would be better to know some basics about thyroid and its functions in the human body and the types of problems it can face.
What is a thyroid?
Thyroid is a butterfly-shaped hormone-secreting gland located on the front part of the neck below the Adam’s apple. It is the master gland of metabolism. The thyroid controls the growth and maturation of body tissues and also controls how quickly the body burns energy, makes proteins and how sensitive the body should be to other hormones.
The thyroid secretes three important hormones, namely, L-thyroxine (T4), triiodothyronine (T3) and calcitonin. Thyroid hormones T3 and T4 play a particularly crucial role in brain development during pregnancy. They also contribute in protein production. Calcitonin is a major regulator of calcium levels in blood.
What are the various thyroid problems?
Thyroid related diseases can be either due to production of too much of thyroid hormones (hyperthyroidism) or too little hormones (hypothyroidism). The tell tale symptom of thyroid problem is Goiter, which is enlargement of the thyroid gland, which can be easily noticed by an obvious swelling in the front of the neck.
When there is too little production of thyroid hormones (Hypothyroidism), it could cause increase of body weight, depression, hair loss, fatigue etc.
When there is excess production of thyroid hormones (Hyperthyroidism), it could cause insomnia, nervousness, loss of mental stability, dry skin, loss of body weight, excessive sweating etc.
Causes of thyroid problems:
Let us first see some causes for thyroid problems leading to under secretion of hormones (hypothyroidism). They are
Worldwide, one major cause of thyroid problem (leading to less than required production of thyroid hormones-) is Iodine deficiency in food intake. Iodine deficiency is more prevalent in mountainous regions. Iodine deficiency shows up through Goiter.
(2) Thyroid surgery:
Hypothyroidism can also happen after a surgery on thyroid glands done to treat Hyperthyroidism, due to excess removal of tissues in surgery.
(3) Congenital:
Hypothyroidism may also congenital (existing from birth) in some cases. There is also one thyroid problem known as Silent Thyroiditis, the cause of which is uncertain, but the condition is believed to be an auto immune disorder triggered by childbirth.
(4) Drug induced Hypothyroidism:
Some medication like lithium can also cause under production of thyroid hormones.
(5) Hashimoto’s Thyroiditis:
Pituitary gland located in the head is actually the controller of the thyroid gland. It produces Thyroid Stimulating Hormone (TSH). If production this hormone increases, it causes the thyroid gland to become hyperactive which eventually results in the failure of the gland and thus ultimately leading to hypothyroidism. This is known as Hashimoto’s disease.
Now let us proceed to see some causes for thyroid problems leading to excess secretion of hormones (hypothyroidism).
(6) Inflammation of thyroid:
This is known as Quervain Thyroiditis. When thyroid gets this problem, it secretes excessive hormones.
(7) Drug Induced Hyperthyroidism:
This is most commonly caused by a heart medication called amiodarone. This can be prevented by monitoring the possible side effects of the drug and weighing it against the benefits of using the heart medication.
(8) Tumor in the pituitary gland:
We have already seen that Pituitary is actually the controller of the thyroid gland. If a tumor develops in the Pituitary gland (Pituitary Adenoma) it leads to over stimulation of the thyroid gland.
(9) Toxic multinodular goiter:
This occurs when part of the thyroid gland produces thyroid hormones all by itself, without any stimulation required by the hormones secreted by the pituitary gland, namely TSH. This is known as Toxic multinodular goiter.
(10) Grave’s disease:
This condition results from abnormal stimulation of the thyroid gland by a material in the blood termed the long-acting thyroid stimulator (LATS). LATS over stimulates the thyroid causing a goiter. It also causes Graves’s eye disease, including a “bug-eyed” look and “frightened stare.” This can progress to severe eye pain or eye muscle weakness. It also causes raised and thickened skin in feet.
Sources:
http://en.wikipedia.org/wiki/Thyroid
Class XII Text book for biology- Year 2004- prescribed as per NCERT Syllabus For India
http://www.emedicinehealth.com/thyroid_problems/article_em.htm
