Understanding Hypothyroidism and Hyperthyroidism

Dr Ben Ng Understanding Hypothyroidism and Hyperthyroidism

The thyroid, a butterfly-shaped gland in the neck, is the unsung hero of our endocrine system. 

Producing hormones that regulate numerous metabolic processes in the body it can sometimes malfunction in one of two ways: it produces too little (hypothyroidism) or too much (hyperthyroidism) of the hormone. Medical Channel Asia invites Dr Ben Ng, Consultant Endocrinologist at Arden Endocrinology Specialist Clinic Mount Elizabeth Novena, to provide key insights into this condition.

Hypothyroidism: The Underactive Thyroid


When the thyroid gland is underactive, it results in hypothyroidism. This condition manifests itself through several symptoms:

  • Fatigue and tiredness
  • Weight gain
  • Cold intolerance
  • Dry skin and hair
  • Muscle aches and cramps
  • Memory problems or difficulty concentrating


The most common cause worldwide is iodine deficiency. However, in countries with adequate iodine intake, Hashimoto’s thyroiditis, an autoimmune disorder, reigns as the primary cause. In this condition, the body’s immune system mistakenly attacks the thyroid gland.

Diagnosis and Treatment

A simple blood test measuring TSH (Thyroid Stimulating Hormone) levels can diagnose hypothyroidism. Once detected, it’s typically treated with synthetic thyroid hormone pills.

Hyperthyroidism: The Overactive Thyroid


Hyperthyroidism occurs when the thyroid gland becomes overactive. Symptoms include:

  • Rapid heartbeat or palpitations
  • Unintended weight loss
  • Increased appetite
  • Heat intolerance
  • Sleep disturbances
  • Frequent bowel movements


Graves’ disease, another autoimmune disorder, is the most common cause. The body’s immune system mistakenly triggers the thyroid to produce too much hormone. Other causes include thyroid nodules and inflammation of the thyroid.


Dr Ben Ng added that a blood test measuring levels of T3, T4, and TSH can help diagnose hyperthyroidism. “Though the most common cause of thyroid disease is autoimmune disease, other conditions such as pituitary disorders and viral thyroid disease can give rise to abnormalities within the thyroid function. Understanding the relationship between the blood tests and, on occasion, radiological tests such as ultrasound on UK uptake scans allows the clinician to diagnose the patient and also follow up on the progress.”


Treatment may range from anti-thyroid medications, beta-blockers, and radioactive iodine to surgery, depending on the cause and severity.

Dr Ng explained that “generally speaking, for patients with an excessive thyroid hormone level, the options for treatment include antithyroid medication, radioactive iodine and surgery. Antithyroid medications are generally safe. However, the medications can cause side effects such as rash, liver inflammation and alterations in the individual’s immunity.”

Surgical options are also available. Dr Ng explained that “for surgical intervention, the surgeon removes the thyroid gland completely, hence resulting in the patient being hypothyroid (underactive) The challenges of surgery are from the procedure itself: Anaesthetic risks, bleeding and infection. The benefits of surgery are that under an experienced hand, the procedure is very successful in treating elevated thyroid levels.

Radio iodine treatment destroys the thyroid gland using iodine labelled with radiation. The thyroid gland is the only part of the body which absorbs iodine. Therefore, when an individual consumes iodine labelled with radiation, this iodine will be absorbed into the thyroid gland, which then gets destroyed by the radiation over time.

The benefit of radiation therapy is that you can achieve the same result of surgery without the risks of anaesthesia, bleeding, et cetera. The downside of radiation is that you may require more than one treatment. Furthermore, many patients who have an overactive thyroid are young ladies who either are of reproductive age or have young children. This can cause challenges from a practical standpoint as they will need to be isolated for some time. Furthermore, we do not recommend young ladies who undergo radioiodine treatment to get pregnant for at least 6 months after the procedure.”


Both hypothyroidism and hyperthyroidism present distinct challenges but are manageable with timely diagnosis and appropriate treatment. Regular medical check-ups, especially for those with a family history of thyroid disorders, are crucial. By understanding the symptoms and seeking medical advice early, individuals can ensure their thyroid remains a steadfast ally in their overall health journey.

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