Thyroid Disorders

Your thyroid gland is a small, butterfly-shaped gland located in your neck just below your Adam’s apple. The thyroid produces hormones that affect your body’s metabolism, which controls how your body uses and stores energy from the food you eat as well as how certain organs function.

When your thyroid is not functioning properly, it can affect:

  • Body weight
  • Energy level
  • Skin
  • Muscle strength
  • Memory
  • Heart rate
  • Cholesterol level

Thyroid problems are very common, especially among women, affecting about one in every eight North American women at some point during their life. However, thyroid problems often are misdiagnosed because their symptoms sometimes develop gradually and are confused with other medical problems.

The most common thyroid disorders occur either when your thyroid fails to produce enough hormones, a condition called hypothyroidism, or when your thyroid produces an excessive amount of hormones, causing hyperthyroidism. Most thyroid disorders can be diagnosed with a simple blood test, called a thyroid stimulating hormone (TSH) test.

Treatment typically involves surgery, medications and radioactive iodine.


Hyperthyroidism occurs when the thyroid produces excess thyroid hormone.

Hyperthyroidism is a common disorder affecting over two million North Americans, most of whom are women.

The most common cause of the condition is Graves’ disease, which accounts for 85 percent of cases. Hyperthyroidism also can result from nodular goiter, a condition in which an inflammation of the thyroid occurs due to viral infections or other causes, ingestion of excessive amounts of thyroid hormone, and ingestion of excessive iodine.

Initially, many patients do not experience any symptoms and therefore do not get diagnosed with hyperthyroidism until it is more advanced. In older people, some or all of the typical symptoms of hyperthyroidism may be absent, and the patient may just lose weight or become depressed.

Typical symptoms of the condition include:

  • Nervousness and irritability
  • Increased resting heart rate, which causes heart palpitations
  • Heat intolerance and increased sweating
  • Tremors
  • Weight loss with increase in appetite
  • Frequent bowel movements
  • Thyroid enlargement causing a lump in the neck
  • Pretibial myxdemia, which causes a thick redness on the front of legs and typically occurs with Graves’ disease
  • Thin, delicate skin and irregular fingernail and hair growth
  • Menstrual disturbance, such as decreased flow
  • Mental disturbances
  • Sleep disturbances, including insomnia
  • Changes in vision, eye irritation or exophthalmos, which is a protrusion of the eyes that typically occurs with Graves’ disease


Hypothyroidism occurs when the thyroid gland fails to produce enough thyroid hormone. Without enough thyroid hormone, the body becomes tired and run down. Every organ system slows, including the brain, which affects concentration; the gut, causing constipation; and metabolism — the rate at which the body burns energy — resulting in weight gain. Although there are many different causes of hypothyroidism, the resulting effect on the body is the same.

The most common cause of hypothyroidism is Hashimoto’s thyroiditis, a disease in which the body’s immune system attacks the thyroid gland. Failure of the pituitary gland to secrete a hormone to stimulate the thyroid gland, called secondary hypothyroidism, is a less common cause of hypothyroidism. Other causes include congenital defects, surgical removal of the thyroid gland, irradiation of the gland and inflammatory conditions.

The condition is more common in women and people over the age of 50. Other risk factors include thyroid surgery and exposure of the neck to X-ray or radiation treatments.

The symptoms of hypothyroidism depend on the amount of decrease in thyroid hormone and the duration of time in which the decrease has been present. Most patients experience mild symptoms, which are often confused with other problems. Symptoms may include:

  • Fatigue
  • Joint or muscle stiffness
  • Decreased hearing
  • Weight gain
  • Dry skin
  • Sensitivity to cold
  • Coarseness or loss of hair
  • Goiter, or an enlarged thyroid causing a lump in the neck
  • Constipation
  • Memory and mental impairment
  • Depression
  • Irritability
  • Irregular or heavy menstruation
  • Slowed heart rate
  • Decreased libido

With proper treatment, patients with hypothyroidism can regain full control of their lives and completely eliminate symptoms.