Thyroid disorders

High levels of thyroid hormone can affect the whole body, and may result in increased body metabolic rate. The causes of hyperthyroidism include:

• Graves' disease - the most common cause. Graves' disease is caused by antibodies in the blood that makes the thyroid produce too much thyroid hormones.
• A solitary toxic thyroid nodule – one thyroid nodule that is producing too much thyroid hormones.
• A toxic multinodular goitre – this is an enlarge thyroid gland that consist of many nodules which are producing too much thyroid hormones.
• Thyroiditis - inflammation of the thyroid gland. With inflammation and damage to the thyroid gland, stored thyroid hormones are leaked resulting in excess thyroid hormone. This is a temporary and self-limiting process.

High level of thyroid hormones results in an increase in the body’s metabolism. Symptoms include:

• weight loss, despite an increased appetite
• palpitations and high pulse rate
• hand tremors
• intolerance to heat and sweating
• tiredness and weak muscles
• irritability, and mood swings
• diarrhoea or loose stools
• warm, moist hands
• thyroid eye disease – a condition in which the eye muscles, eye lids, tear glands and fatty tissue behind the eye become inflamed.

The choice of treatment will depend on several factors such as your age, the type and severity of hyperthyroidism, other medical conditions that may be affecting your health, and your preference.

The available treatments options include:

• Antithyroid medications to reduce the production of thyroid hormones
• Surgery to remove part or all of the thyroid gland
• Radioactive iodine

The cause of thyroid nodules is unknown. Thyroid nodules however are common and increases with age. Most thyroid nodules are harmless, but it is best to have them checked in case they are among the few that are cancerous.

Most thyroid nodules do not cause symptoms. There are some thyroid nodules that may produce excess amounts of thyroid hormone causing hyperthyroid symptoms (see section on hyperthyroidism).

• pain in the neck, jaw, or ear.
• difficulty with breathing, or swallowing (if nodule is large and compressing on the wind/food pipe).
• voice hoarseness (if the nodule invades the nerve that controls the vocal cords - this is usually related to thyroid cancer).

• Thyroid function test (blood test)
• Thyroid ultrasound scan - to characterise the nodules.
• Fine needle aspiration cytology (FNAC) – this is a bedside procedure usually done under ultrasound where a thin needle is used to obtain cells from the thyroid nodules. Several samples will be taken from different parts of the nodule to give the best chance of finding cancer cells if they are present. The cells are then examined under a microscope.
• Thyroid nuclear scan - this scan examines if the nodules are overactive (‘hot’) or under-active (‘cold’).
  

Patients with benign thyroid nodules are usually monitored with ultrasound surveillance. Those with suspicious thyroid nodules are usually recommended for surgery.

The treatment of thyroid nodules that produce excess hormone (toxic thyroid nodule/toxic multinodular goitre) can be found under section on hyperthyroidism.