What are the other Names for this Condition? (Also known as/Synonyms)
- Lymphocytic Thyroiditis
- Painless Thyroiditis
- Subacute Lymphocytic Thyroiditis
What is Silent Thyroiditis? (Definition/Background Information)
- Subacute Thyroiditis is disorder of the thyroid gland. It is a variant of Hashimoto’s disease. There are many subtypes of subacute thyroiditis and they include the following:
- Silent Thyroiditis
- Postpartum Silent Thyroiditis
- Silent Thyroiditis is a condition in which there is inflammation of the thyroid gland. It most commonly occurs in middle-aged women
- Generally, in subacute thyroiditis, the thyroid gland is painful; whereas, in Silent Thyroiditis, it is painless, and hence, the condition is called ‘silent’
- The cause of the condition is unknown; however, there are a variety of risk factors that contribute towards Silent Thyroiditis development. These include certain autoimmune disorders, discontinuation of steroid therapy, cancer treatment, removal of the adrenal gland for other health condition, and many other factors
- The disorder usually results in hyperthyroidism (increased functioning of thyroid gland) followed by hypothyroidism (decreased functioning of the gland), before returning to a state of normally functioning thyroid gland
- The common signs and symptoms of Silent Thyroiditis include weight loss, increased sweating, fatigue, irritability, irregular menstrual periods in women and nervousness
- A diagnosis of Silent Thyroiditis is made by measuring the thyroid hormone levels in blood and through an ultrasound scan of the thyroid gland
- The signs and symptoms related to Silent Thyroiditis usually resolve within 3 months. The prognosis of Silent Thyroiditis is excellent and most individuals do not need any specific treatment
Who gets Silent Thyroiditis? (Age and Sex Distribution)
- Individuals of all ages may be affected by Silent Thyroiditis. However, the incident rate is higher among middle-aged adults
- Silent Thyroiditis more often affects females (especially middle-aged women) than males
- Individuals of all racial and ethnic groups are affected
What are the Risk Factors for Silent Thyroiditis? (Predisposing Factors)
Risk factors associated with Silent Thyroiditis include:
- Female gender
- Family history of Silent Thyroiditis
- Autoimmune disorders including systemic lupus erythematosus
- Cancer patients who undergo radiation therapy for Hodgkin’s lymphoma
- Immune thrombocytopenia
- Following stoppage of steroid therapy (usually long-term), which is administered for a variety of reasons
- Those who have undergone adrenal gland removal surgery for Cushing syndrome
- Lithium treatment in some individuals
It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.
Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.
What are the Causes of Silent Thyroiditis? (Etiology)
- The exact cause of Silent Thyroiditis is unknown
- It is believed to develop due to an immune attack against the thyroid gland due to hyperactivity of the individual’s own immune system; it is an autoimmune disorder
What are the Signs and Symptoms of Silent Thyroiditis?
In the beginning of Silent Thyroiditis, it causes hyperthyroid signs and symptoms. This state is known as the hyperthyroid state. As the condition progresses, it causes hypothyroid signs and symptoms, a state known as hypothyroid state. Frequently, the signs and symptoms of Silent Thyroiditis are mild.
Hyperthyroidism symptoms usually last for 3 months or less. The associated signs and symptoms of hyperthyroidism may include:
- Sleeping difficulties including insomnia
- Excess sweating and intolerance to heat
- Increased to excessive hunger
- Irritation, restlessness, and nervousness
- Protrusion of the eyes
- Menstrual abnormalities in women; menstruation may be irregular or short
- Abnormal heartbeat rate including rapid heart rate
- Sudden weight loss
As the condition progresses, it leads to hypothyroidism, and the signs and symptoms associated with this condition may include:
- Enlarged or swollen thyroid gland; small or shrunken thyroid gland (late in the disease)
- Difficulty concentrating or thinking
- Fatigue and tiredness
- Dry skin
- Hair loss, which may be in excess while showering
- Constipation or difficult bowel movements
- Weight gain that may be slow and gradual
- Heavy and irregular periods (in women)
- Abnormal sensitivity to cold; the affected individuals may not tolerate cold very well
How is Silent Thyroiditis Diagnosed?
In order to diagnose Silent Thyroiditis (in women) and not post-partum Silent Thyroiditis, the women should not have been pregnant within the last one year period. This means that the women should NOT have had the following events in their recent history:
- Termination of pregnancy
Silent Thyroiditis can be diagnosed with a simple physical examination and a thorough medical history. Some of the signs and symptoms noted may include:
- An enlarged thyroid gland
- Elevated heart rate
- Shaking hands
In most cases, no tests are required to diagnose the condition. However, the following diagnostic tests may be ordered, when necessary:
- Blood test to assess increase in levels of thyroid hormones T3 and T4
- Radioactive iodine uptake
- Ultrasound scan of the thyroid gland
Note: Thyroid scintigraphy is helpful in differentiating Silent Thyroiditis from Grave’s hyperthyroidism. This is because in Silent Thyroiditis the scintigraphy will show low accumulation of radiotracer on the technetium scan. In Grave’s disease, there is increased accumulation of the radiotracer on the scan.
Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.
What are the possible Complications of Silent Thyroiditis?
Silent Thyroiditis is a generally self-limiting condition. However, sometimes, the thyroid function does not completely come back to normal levels. In such individuals, hypothyroidism may persist permanently.
Some potential complications associated with hypothyroidism include:
- Heart diseases
- Increased risk of infection
How is Silent Thyroiditis Treated?
In many cases, Silent Thyroiditis is a self-limiting condition that resolves on its own. If treatment is provided, then it is based upon the presenting symptoms:
- Beta-blockers are known to relieve an elevated heart rate and excessive sweating
- Sometimes, thyroid hormone replacement is needed, if symptoms of hypothyroidism persist
- Follow-up care with screening and check-ups are important at regular intervals
- No surgery is required and surgery should be avoided
- No radioactive iodine treatment is necessary
- During the hyperthyroid stage, anti-thyroid drugs are not necessary
How can Silent Thyroiditis be Prevented?
The exact cause of Silent Thyroiditis is not known, and hence currently, there is no known preventive method reported for the condition.
What is the Prognosis of Silent Thyroiditis? (Outcomes/Resolutions)
- In most cases, Silent Thyroiditis has the ability to go away on its own within a year. The acute phase typically ends within a 3-month period. In such cases, the prognosis of Silent Thyroiditis is excellent
- 80% percent of the patients show a complete recovery. Some may develop hypothyroidism over time
- As the condition resolves on its own, in a majority of individuals, the thyroid gland function comes back to normalcy (euthyroid state)
- A close follow-up is necessary with 6 month intervals; during the follow-up visits, thyroid hormone levels in blood should be checked
Additional and Relevant Useful Information for Silent Thyroiditis:
Postpartum Silent Thyroiditis is an autoimmune thyroid disorder that affects women in the period following pregnancy, or the postpartum period.