Thyroid Conditions

The main thyroid diseases that have been classified include:
Hypothyroidism – when the thyroid is underactive and not functioning adequately, leading to a decrease in hormone production, such as the thyroid hormone. This is the most common form of thyroid dysfunction^2,2
Hyperthyroidism – when the thyroid is overactive and produces too much thyroid hormone³
Thyroid nodules – abnormal lumps/growths on the thyroid gland³
Thyroiditis – inflammation of the thyroid gland³
Over-medication with thyroid hormone³

There are various causes of hypothyroidism (with subsequent decrease in thyroid hormone levels), including:
Iodine deficiency, as the thyroid gland needs iodine to produce its hormones, including thyroid hormone⁴
Auto-immune condition known as Hashimoto thyroiditis, where the body’s own defence system attacks the thyroid gland, damaging the gland, impacting its ability to function properly and produce thyroid hormone^{6, 7}
Surgical removal of the thyroid gland
Radioiodine treatment of the thyroid gland (often used for treating hyperthyroidism of cancer of the thyroid gland)
Radiation therapy to the head or neck
Being born without a thyroid gland⁸
Disease to either the pituitary gland or hypothalamus in the brain, because the aforementioned organs stimulate the thyroid gland to function properly²
Postpartum thyroiditis – This is a condition that occurs in young mothers after giving birth and may include both hypothyroidism and hyperthyroidism. Postpartum thyroiditis can be a temporary condition or it can develop into long-term hypothyroidism⁶

People with an underactive thyroid may experience the following:^2,6

• Lack of energy
• Slow metabolism resulting in weight gain
• Lack of energy
• Thinning hair
• Hoarseness
• Increased sensitivity to cold
• Slow heart rate less than 60 beats per minute
• Depression
• Impaired memory
• Pain, stiffness and swelling of muscles and joints
• Dry, puffy, pale skin

If you experience some of the above signs and symptoms, consult your doctor.

Although anyone can develop hypothyroidism, the following may increase your risk:^{3, 10}

• Affects females more than males
• History of an autoimmune condition
• Family history of thyroid disease
• Received radiation (neck) or radioactive iodine therapy
• Thyroid surgery
• Pregnancy

• Diagnosing hypothyroidism is usually straightforward by means of a blood test, measuring the hormone thyrotropin (THS).
• TSH is produced by your pituitary gland to signal your thyroid gland to release more or less thyroid hormone.
• A TSH level within the normal range (0.4–2.5 mU/l) will exclude any significant malfunction of your thyroid gland.
• If the TSH level is just above the upper range of normal (above 2.5 mU/l), it is possible that you may develop hypothyroidism in the future.
• If the TSH level is elevated (above 4 mU/l), it is quite likely that you suffer from hypothyroidism, in which case more tests are now needed to confirm the diagnosis, assess the degree and determine the cause.³

Hypothyroidism is treated by means of thyroid hormone replacement therapy, replacing what the body cannot produce on its own.¹¹

• The thyroid pre-hormone levothyroxine is usually effective on its own in the treatment of hypothyroidism.¹¹
• In rare occasions levothyroxine needs to be combined with triiodothyronine (T3) in order to achieve optimal metabolic control.⁶

Hyperthyroidism occurs for different reasons compared to hyperthyroidism:
The most common cause (up to 70% of all cases) is a disease of the immune system called Graves’ disease. Graves’ disease tends to run in families and occurs more frequently in young women.³

Symptoms usually vary, but may include:³

• Weight loss
• Insomnia
• Irritability
• Excessive sweating

Treatment is aimed at reducing the over-production of thyroid hormones, and treatment options include the following:³

• Anti-thyroid medication
• Radioactive iodine treatment
• Surgical removal of the thyroid gland or nodule