CLINICAL SERVICES

Thyroid Disorders

THYROID DISORDERS

The thyroid is a small butterfly-shaped gland in the front of the neck. It produces two hormones (T3 and T4) that are carried in the bloodstream to all tissues of the body. These hormones control many things including:

  • Metabolic activity
  • Body weight and temperature
  • Heart rate and blood pressure
  • Mental alertness
  • Growth in children

INTERNAL MEDICINE

DIABETES

ENDOCRINOLOGY

The thyroid is under the control of the pituitary gland via TSH (thyroid stimulating hormone). The thyroid can become underactive (hypothyroid), or overactive (hyperthyroid), and it can develop nodules. Other problems include thyroiditis (inflammation of the gland) and thyroid cancer. Goitre is a medical term to describe an enlarged thyroid.

+Hypothyroidism (underactive thyroid)

This occurs when too little thyroid hormone is produced and has a number of causes, including Hashimoto’s disease, in which the immune system attacks the gland. The lack of hormone slows metabolism and may be associated with the following symptoms:

  • Fatigue
  • Mental depression
  • Poor memory
  • Sluggishness
  • Feeling cold
  • Weight gain
  • Dry skin and hair
  • Constipation
  • Menstrual irregularities

Treatment of hypothyroidism is by replacing the hormone the body needs, usually through tablets of T4 (thyroxine). Use of T3 (liothyronine) is controversial and not routinely indicated.

+Hyperthyroidism (overactive thyroid)

This is caused by too much thyroid hormone. One of the commonest causes is Grave’s disease, an autoimmune condition. Other causes include nodules and inflammation. Excess thyroid hormone speeds up metabolism, causing abnormal function in many body systems. Symptoms may include:

  • Fatigue
  • Weight loss
  • Tremor
  • Rapid heartbeat
  • Irritability and anxiety
  • Muscle weakness
  • Eye problems (irritated/swollen eyes or difficulty seeing)
  • Menstrual irregularities
  • Intolerance to heat and increased sweating
  • Diarrhoea or frequent bowel movements
  • Fertility difficulties

Treatment options include antithyroid drugs, Beta-blockers (to control symptoms), radioactive iodine, or surgery.

+Thyroid nodules and cancer

Thyroid nodules are common, and the vast majority are not harmful or cancerous. About 5% of thyroid nodules are cancerous and most patients with thyroid cancer recover well with appropriate treatment. Anyone with a thyroid nodule should be assessed and if necessary investigated to rule out cancer.