April 27, 2016 486
Thyroid gland is an important part of endocrine system. It is situated below the larynx, at either side of the trachea. The main function of thyroid gland is to regulate metabolism in our body. Hyperthyroidism is a condition characterized by overactive thyroid gland. As a result, thyroid gland starts producing too much thyroid hormone than our physiological need. This condition is also sometimes referred to as thyrotoxicosis.
What causes Hyperthyroidism?
Hyperthyroidism can be caused by a number of factors, including:
- Graves’ disease (an autoimmune disease and the most common cause of hyperthyroidism)
- Inflammation of the thyroid/thyroiditis (could be due to viral infection, some medications or occurs after pregnancy)
- Too much iodine consumption (Iodine is an essential component in synthesis of thyroxine hormone)
- Medication used to treat hypothyroidism
- Pituitary adenoma: non cancerous growth of thyroid or pituitary gland (rare)
- Certain tumour of the testes/ovaries (rare)
- Contrast dye that has iodine in medical imaging tests (this is very rare)
How would I know if I am suffering from hyperthyroidism?
The symptoms for this condition might vary from one person to another, however there are a few common symptoms associated to this condition. They are:
- Nervous emotional state, irritability
- Rapid, irregular heartbeat
- Frequent bowel movements
- Increased appetite, decreased weight
- Intolerance to heat
- Hand tremors
- Goitre (Swollen neck due to enlarged thyroid gland and the swelling may interfere with breathing or swallowing)
- Sleeping problem
- Fatigue/muscle weakness
- Exophthalmos (bulging of the eyes due to deposition of fats behind the eyeballs)
How to diagnose this condition?
Many of the symptoms of hyperthyroidism are similar to other diseases, so this condition cannot be diagnosed based only on the symptoms alone. Apart from taking medical history and physical examination, there are a few blood tests taken to confirm if someone is suffering from hyperthyroidism. The tests taken for the diagnosis of hyperthyroidism are described below:
- TSH (Thyroid stimulating hormone) test: Gold standard test. Most accurate indicator of thyroid activity. TSH level below than normal suggests possibility of hyperthyroidism. Has high sensitivity and the ability to detect even mild hyperthyroidism.
- T3 and T4 test: T3 is triiodothyronine and T4 is thyroxine, both are thyroid hormones and increased level of one of these or both is indicative of hyperthyroidism.
- Thyroid-stimulating Immunoglobulin (TSI) test: People with Graves’ disease have higher concentration of circulating TSI. In hyperthyroidism caused by other conditions TSI level is not elevated.
- Radioactive Iodine Uptake Test: Measures the amount of iodine taken up by thyroid cells from the blood. Low level of iodine uptake might indicate thyroiditis whereas higher level is suggestive of Graves’ disease.
- Thyroid scan: Identifies distribution of iodine in the thyroid. Helps in diagnosing the cause of hyperthyroidism.
What are the risk factors for hyperthyroidism?
Do you know that women are 2 to 10 times more likely to develop hyperthyroidism? But being a woman is not the only risk factor for this disorder; there are other groups of people who are also predisposed to higher risk of developing hyperthyroidism. People in the following groups are advised to do regular testing given that they are at higher risk of developing this condition:
- Family history of thyroid disease
- Have history of thyroid problem
- Have auto-immune disease such as Addison’s disease and Type 1 Diabetes Mellitus
- Takes high amount of iodine, it could be from the food or medications (e.g: amiodarone) consumed
- Older than 60 years old
- Women after pregnancy
- Have pernicious anaemia, vitamin B12 deficiency, primary adrenal insufficiency (a hormonal disorder)
- People who smoke - This group of people are more prone to develop Graves’ disease
How does hyperthyroidism affect older people?
The symptoms presented by older people suffering from hyperthyroidism can be different from the common symptoms listed above. Deterioration of intellectual ability, emotional distress and behavioural changes exhibited by the older people can at times lead to misdiagnosis of the condition to be depression or dementia. Elderly with this disorder might also present symptoms such as lack of interest, social withdrawal and loss of appetite. In people aged 60 and above, subclinical hyperthyroidism increases the risk of developing a rapid, irregular heartbeat (atrial fibrillation) and increases the risk of heart failure or stroke. Increased production of thyroid hormones also speeds up osteoporosis (bone thinning disease) especially in women if left untreated.
Does thyroid affect pregnant women?
The answer is yes, but not all! Hyperthyroidism due to Graves’ disease occurs in every 500 pregnancies. Miscarriage, pre-term delivery and preeclampsia (lethal increase in blood pressure during late pregnancy) are some of the risky consequences if hyperthyroidism is not controlled in pregnancy. Women with hyperthyroidism should discuss their health condition with their doctor before becoming pregnant. Assessing hyperthyroidism in pregnant women can be difficult because thyroid gland enlargement occurs even for healthy women in pregnancy. So, watch out for distinguishable symptoms like irregular heartbeat, slight tremor or failure to gain pregnancy weight as signs of hyperthyroidism development. Always consult your doctor when you suspect of having symptoms relating to hyperthyroidism. Postpartum (after pregnancy) thyroiditis is something worth watching out for as it affects 4-10 % of women in the first year after giving birth. Postpartum thyroiditis can also cause hyperthyroidism.
How can diet help in managing hyperthyroidism?
Eating balanced, nutritious diet is important not just in managing hyperthyroidism but to ensure general health of an individual. Since iodine is essential mineral for thyroid, taking food rich in iodine such as seaweed, dulse and kelp may cause or aggravate hyperthyroidism. However, women need more iodine during pregnancy (about 250 micrograms) to supply the foetus with sufficient iodine for growth. Choosing iodized salt (salt supplemented with iodine) and prenatal vitamins containing iodine can aid in meeting the required iodine level. However, always keep in mind to consult a doctor or nutritionist before taking any of these (if you are already suffering from hyperthyroidism especially), as excessive level of iodine will worsen the disorder.
Can Hyperthyroidism be treated?
Yes, anti-thyroid medications, radioiodine therapy and thyroid surgery are the three most common types of therapies adapted by healthcare providers to treat this condition. So, always get yourself checked by your doctor when there are signs or symptoms of hyperthyroidism. Remember, for any health condition, early detection is just as good as prevention.
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National Institute of Diabetes and Digestive and Kidney Disease
by Thanusha Ganesan
Final year pharmacy student. Highly curious and immensely enthusiastic. I strongly believe that to be happy is to indulge in the spirit of giving. View all articles by Thanusha Ganesan.