HYPERTHYROIDISM
HYPERTHYROIDISM
- Hyperthyroidism (overactive thyroid) occurs when the thyroid gland produces excess amount of thyroid hormones
- Hyperthyroidism can accelerate body’s metabolism, resulting in unintentional weight loss and a rapid and irregular heartbeat
- Although hyperthyroidism can be dangerous if ignored, most patients respond well once hyperthyroidism is diagnosed and treated
Hyperthyroidism may mimic other health problems which makes its diagnosis difficult. It can cause a wide range of symptoms which include:
- Unintentional weight loss, inspite of increased appetite/food intake
- Palpitations, Rapid and irregular heartbeat
- Sweating, Nervousness, anxiety and irritability
- Tremor – usually a fine trembling in the hands and fingers
- Changes in menstrual patterns
- Increased sensitivity to heat
- Changes in bowel patterns, especially more frequent bowel movements
- An enlarged thyroid gland (goiter), which may appear as a swelling at the base of your neck
- Fatigue, muscle weakness and difficulty in sleeping
- Skin thinning, brittle hair
Hyperthyroidism may be caused by :
- Graves’ disease
- Toxic adenoma and toxic multinodular goiter
- Inflammation of the thyroid (thyroiditis)
Hyperthyroidism is diagnosed by:
1. Medical history and physical examination
2. Blood tests to confirm the diagnosis
- Thyroid function tests : low TSH and elevated FT4 and T3 confirms Hyperthyroidism
- Thyroid Antibody profile: Elevated Thyroid Stimulating Immunoglobulin and Thyroid Peroxidase Antibody confirm Grave’s disease
3. Radioactive Iodine Scan
- A high uptake of Radioiodine indicates increased thyroid hormone production likely caused by either Grave’s disease or Hyperfunctioning thyroid nodules
- A low uptake of Radioiodine indicates that the thyroid hormones stored in the thyroid are leaking into blood stream likely caused by thyroiditis
4. Ultrasound of neck (Thyroid and lymph nodes)
Treatment options include:
- Antithyroid medications- These drugs gradually reduce the symptoms of hyperthyroidism by blocking excess amounts of hormones production in thyroid
- Beta blockers– These drugs ease symptoms of hyperthyroidism such as a tremors, rapid heart rate and palpitations
- Radioactive iodine- Radioactive iodine is absorbed by the thyroid gland, where it causes gradual destruction of thyroid cells. Symptoms usually subside within several months but repeated doses may be required and may result in hypothyroidism
- Surgery- Surgery is specifically indicated in those with large thyroid glands, grave’s associated with eye disease, those who are pregnant or planning pregnancy within one year
GRAVES’ DISEASE
- Graves’ disease is an autoimmune disorder that results in the overproduction of thyroid hormones (hyperthyroidism)
- It can be diagnosed with a blood test that measures the antibody produced against the thyroid called thyroid stimulating immunoglobulin (TSI)
- The disease can be managed medically (anti-thyroid medication), with radioactive iodine therapy as well as surgically. Comprehensive evaluation and personalized treatment plan is necessary in the management and cure. Graves’ disease requires total removal of the thyroid gland and should only be performed by expert thyroid specialist surgeons
Quick Facts
- Most common cause of hyperthyroidism (excess thyroid hormone production)
- An autoimmune condition caused by thyroid stimulating immunoglobulin
- TSI appears to have some ability to bind to the TSH receptor on the thyroid cells resulting in hyperthyroidism
- Women are more affected than men
- May have some hereditary component
- Diagnosed by low TSH, high Free T4, presence of anti-thyroid antibodies and typical clinical features
Common symptoms include:
1. Thyroid hormone excess that may cause:
- Unexplained weight loss inspite of excessive appetite
- Heat intolerance or excessive sweating
- Anxiety, Nervousness, Tremors, Restlessness
- Muscle weakness, tiredness
- Difficulty sleeping at night
- Increased or irregular heart rate, palpitations or chest pain
- Change in menstrual periods
- Increased frequency of bowel movements
2. Diffuse thyroid swelling that may cause:
- Difficulty swallowing
- Change in voice
- Tenderness
- Shortness of breath
3. Changes to the Eyes : Graves’ Opthalmopathy
- Mild eye symptoms : Redness, dryness, Excessive tearing
- Severe eye symptoms
- Blurred vision
- Double vision
- Protruding of the eyes
4. Skin changes
- Thickening of the skin of the lower leg : called pretibial myxedema
- Patchy and red skin lesions
Although anyone can develop Graves’ disease, the risk is increased if you are:
- Woman
- Younger than 40years of age
- Have a family history of Graves’ disease
- Suffering from autoimmune diseases such as type 1 diabetes or rheumatoid arthritis
- Pregnant or have delivered a baby within the past six months
- Susceptible to emotional or physical stress
- Cigarette smoker
Graves’ disease is an autoimmune condition where antibody (TSI) is produced against the thyroid gland. The exact cause for this is not known. TSI appears to have some ability to bind to the thyroid cell TSH receptor just as TSH will do. The Thyroid stimulating immunoglobulin stimulates the thyroid cells to produce hormone in a continuous and unregulated fashion
The following investigations help diagnose Graves’ disease:
- Complete medical history and physical examination
- Thyroid function tests- Low TSH with Elevated FT4, T3
- Thyroid Antibody profile- Elevated levels of Thyroid Stimulating Immunoglobulin (TSI) and Thyroid Peroxidase Antibody(TPO)
- Ultrasound of neck (Thyroid and lymph nodes)- Thyroid gland is enlarged and hyperechoic with a heterogenous echotexture and hypervascularity
- Radioactive Iodine Scan- Homogenously increased activity in an enlarged thyroid gland
Homogenously increased uptake of iodine throughout the thyroid gland is suggestive of Graves’ disease
The treatment goals are to stop the production of thyroid hormones and to block the effect of the hormones on the body. Treatment options include
1. Antithyroid Medication
- Drugs like methimizole and propthiouracil gradually block excess amount of hormone production in thyroid. Drugs usually take few weeks to work and are considered as a “short term solution”. Hyperthyroidism generally returns following stoppage of these drugs
- There are few side effects of antithyroid medications like allergy, gastritis and rarely agranulocytosis. If you develop fever, cough, or cold symptoms while on these medications, contact your thyroid specialist immediately
2. Beta blockers
- Beta blockers like Propranolol and Metaprolol do not inhibit the production of thyroid hormones, instead they block the effect of thyroid hormones on the body
- They provide relatively rapid relief of symptoms like irregular heartbeats, tremors, anxiety, sweating, and muscle weakness
3. Radioactive Iodine Therapy
- Radioactive iodine is taken up into the thyroid hormone producing thyroid cells and a radiation effect is produced which gradually destroys the overactive thyroid cells. This therapy may take months to actually produce the desired effect and repeated treatments may be required
- Radioiodine therapy may increase the risk of new or worsen symptoms of Graves’ ophthalmopathy. It is contraindicated in pregnant women and those planning pregnancy within one year and in patients with graves’ ophthalmopathy
- Radioactive iodine therapy may result in hypothyroidism in few patients
4. Surgery
Surgery may be recommended for many reasons:
- Surgery is hundred percent effective in Graves’ disease
- Thyroid surgery is the preferred option in large thyroid glands
- Thyroid surgery is the best option in patients with eye disease
- In patients where antithyroid medication and radioactive iodine may be ineffective
- In patients who cannot take or tolerate antithyroid medication and radioactive iodine
- Surgery requires a total thyroidectomy
- Graves’ disease surgery should be performed by expert thyroid surgeons
- Requires lifelong thyroid hormone medications and monitoring following surgery
