Hypothyroidism, also known as underactive thyroid, is a common condition where the thyroid gland does not produce enough thyroid hormone. Thyroid hormone regulates many important body functions including metabolism, heart rate, body temperature, and growth and development. When the thyroid gland fails to produce adequate amounts of hormones, it can lead to a variety of symptoms including fatigue, weight gain, feeling cold, dry skin, hair loss, and depression. Hypothyroidism is most often caused by Hashimoto’s thyroiditis, an autoimmune disease in which the body attacks its own thyroid tissue. However, it can also be caused by surgical removal of the thyroid, radiation treatment of the thyroid, and certain medications. Once hypothyroidism develops, it has traditionally been viewed as a permanent, lifelong condition that requires daily treatment with thyroid hormone replacement medication. However, some emerging research has suggested that in certain circumstances, hypothyroidism may reverse on its own without medication. This article will examine the evidence on whether hypothyroidism can truly reverse itself.
Can the underlying cause of hypothyroidism resolve?
For hypothyroidism to reverse and thyroid hormone levels to normalize, the underlying cause would need to resolve. Let’s examine some of the common causes of hypothyroidism and whether the underlying condition can improve.
Hashimoto’s thyroiditis
Hashimoto’s is the most common cause of hypothyroidism. With Hashimoto’s, the immune system mistakenly attacks and slowly damages the thyroid gland, leading to impaired hormone production over time. Once significant thyroid damage occurs, the hypothyroidism has traditionally been viewed as irreversible. However, recent research has revealed that in some cases, Hashimoto’s may go through periods of remission where thyroid antibodies decline and thyroid functioning improves.
One study followed euthyroid (normal thyroid) subjects with thyroid antibodies for 5 years. At the end of the study period, 18% of subjects with high antibody levels had developed hypothyroidism as expected. However, 32% went into remission and their antibodies declined or disappeared. The study proposed that Hashimoto’s progresses in a wave-like pattern of recurring inflammation interrupted by periods of remission, rather than inevitably worsening over time.
This indicates there is a chance for Hashimoto’s thyroiditis to spontaneously reverse and restore normal thyroid functioning at least temporarily. However, for most patients the condition eventually progresses to permanent hypothyroidism. More research is still needed to understand what causes periods of remission in Hashimoto’s.
Thyroid surgery
Hypothyroidism is a common complication after thyroid surgery. When a portion or all of the thyroid gland is surgically removed, thyroid hormone levels can drop below normal ranges. In most cases, the hypothyroidism resulting from surgery is considered permanent and requires lifelong thyroid hormone therapy.
However, one scenario where surgical hypothyroidism could potentially reverse is with thyroid lobectomies. A lobectomy involves removing only one lobe of the thyroid, usually to remove cancerous nodules while preserving thyroid functioning. One study found that around 13% of patients who had one thyroid lobe removed were able to maintain normal thyroid functioning without medication after 1 year. The remaining thyroid lobe was able to compensate and produce adequate hormone levels. However, the majority still progressed to hypothyroidism and required treatment.
While reversals are rare, it shows recovery is possible in a subset of patients who have partial thyroid removal. Complete reversal of hypothyroidism after full thyroidectomy (total thyroid removal) is unlikely. The entire gland must be present in order for sufficient hormone production to potentially occur.
Radioactive iodine treatment
Radioactive iodine therapy is used to shrink overactive thyroid tissue, most often to treat hyperthyroidism in Graves’ disease. However, destroying too much tissue can result in shifting from hyperthyroidism to hypothyroidism. Research shows that around 50% of Graves’ disease patients who received radioactive iodine treatment progressed to permanent hypothyroidism within 1 year and required lifelong thyroid hormone therapy.
For the other 50% of patients, thyroid functioning may improve back to normal ranges once the treatment wears off. However, relapse of Graves’ disease is common. One study found relapse rates of 35% at 5 years and 60% at 8 years after radioactive iodine treatment. If the hyperthyroidism recurs, additional radioactive therapy would increase chances of developing permanent hypothyroidism.
So while thyroid function may recover and hypothyroidism reverse temporarily after radioactive iodine, long-term hypothyroidism is still likely over time in Graves’ disease patients treated with this therapy.
Medication-induced hypothyroidism
Some medications can disrupt thyroid hormone production and cause drug-induced hypothyroidism. Examples include lithium, amiodarone, interferon-alpha, interleukin-2, and thalidomide. In most cases, hypothyroidism secondary to these medications is reversible after stopping the drug. Thyroid functioning generally improves back to normal over weeks to months if the drug is discontinued.
One study on long-term lithium treatment found that hypothyroidism reversed in around 2/3 of patients when lithium was withdrawn. The longer the duration of lithium therapy, the lower the recovery rate. After 10-20 years on lithium, full recovery rate dropped to 44%.
Therefore, medication-induced hypothyroidism can potentially reverse once the causative drug is stopped. However, the likelihood of recovery declines with longer exposure.
Can transient hypothyroidism resolve on its own?
Most hypothyroidism is permanent and progressive without treatment. However, temporary forms of hypothyroidism may resolve as the underlying cause resolves or dissipates. Some potential causes of transient hypothyroidism include:
– Postpartum thyroiditis: Swings in hormone levels can trigger thyroid inflammation after pregnancy. Postpartum hypothyroidism resolves on its own within 12 months for most women.
– Subacute thyroiditis: Viral infections can cause temporary thyroid inflammation and hypothyroidism. Resolves in 6-18 months.
– Drug-induced hypothyroidism: As discussed above, hypothyroidism related to lithium, amiodarone, interferon-alpha, interleukin-2 use is reversible with medication cessation.
– Iodine excess: High iodine exposure can temporarily inhibit thyroid hormone synthesis and cause hypothyroidism. Resolves within weeks to months after iodine exposure is reduced.
– Thyroid suppression therapy: Intentionally suppressing thyroid function with medications to treat conditions like thyroid cancer or nodules. Hypothyroidism reverses when therapy is stopped.
– Recovery after thyroiditis: Hypothyroidism may slowly recover after Hashimoto’s or subacute thyroiditis runs its course, though it can take months.
– Central hypothyroidism: Secondary hypothyroidism caused by pituitary gland dysfunction may resolve if the underlying pituitary disorder improves.
Therefore, transient hypothyroidism caused by these reversible factors may resolve without treatment as the underlying trigger resolves. However, delayed or inadequate treatment of transient hypothyroidism can potentially result in permanent, irreversible thyroid damage.
Is permanent hypothyroidism ever reversible?
For most patients with permanent primary hypothyroidism or Hashimoto’s thyroiditis, thyroid damage is considered irreversible. The thyroid gland is often too damaged or inflamed to recover normal functioning. However, some emerging research has begun to challenge the notion that hypothyroidism is always irreversible.
Some small observational studies have reported cases of levothyroxine-treated hypothyroid patients later regaining normal thyroid hormone levels after stopping medication, even after taking it for years. One study described four women with Hashimoto’s thyroiditis who discontinued levothyroxine after taking it for 4-6 years. Surprisingly, all four maintained normal thyroid functioning without therapy during 1-2 years of follow-up.
Another small study followed 10 people with hypothyroidism who stopped taking levothyroxine after an average of 8.6 years. At the end of 6 months off medication, 5 remained euthyroid with normal thyroid tests.
While most patients in these studies eventually relapsed, it suggests that in rare cases, Hashimoto’s may go into prolonged remission and previously hypothyroid patients can recover some thyroid functioning. However, this phenomenon has not been proven in large controlled studies. The risk of stopping medication is developing symptoms or complications of prolonged untreated hypothyroidism. More rigorous research is needed to determine whether permanent hypothyroidism can truly reverse itself spontaneously.
One theory is that levothyroxine therapy may provide a “rest period” that allows some thyroid recovery. But current evidence overall still indicates that most hypothyroidism patients require lifelong treatment.
Role of diet and lifestyle in hypothyroidism reversals
While more research is needed, some functional and integrative medicine practitioners believe that diet, lifestyle, nutraceuticals, and resolving underlying causes may help facilitate reversal or remission of Hashimoto’s thyroiditis. Some interventions proposed to help optimize thyroid health include:
Nutrient-rich diet
Eating an anti-inflammatory diet rich in fruits, vegetables, whole grains, lean protein, nuts, seeds. This provides antioxidants and nutrients that support thyroid function like iodine, selenium, zinc, iron, omega-3s, vitamin D, B vitamins.
Avoiding goitrogens
Goitrogens are substances that may suppress thyroid function by blocking iodine absorption. Limiting raw cruciferous vegetables, soybeans, millet, peanuts and avoiding eating large amounts in one sitting.
Gut health
Correcting bacterial or parasitic infections, leaky gut syndrome and food sensitivities that trigger autoimmunity.
Reducing stress
Chronic stress raises cortisol and inflammation, which can exacerbate Hashimoto’s. Stress management techniques help modulate the immune system.
Moderate activity
Regular exercise reduces inflammation but overtraining can increase cortisol and worsen thyroiditis.
Adequate sleep
Getting 7-9 hours of quality sleep allows thyroid hormone regulation to normalize.
Nutraceutical support
Selenium, probiotics, omega-3s, vitamin D, and adaptogens may support a healthy immune response.
However, most endocrinologists remain skeptical that lifestyle interventions alone can reverse advanced hypothyroidism without medication. More research is needed on the efficacy of conservative approaches for restoring thyroid function.
Conclusion
Mainstream medicine has long regarded hypothyroidism as an irreversible, lifelong condition requiring daily medication. However, emerging research paints a more nuanced picture showing hypothyroidism reversals may be possible in some scenarios. Cases of transient hypothyroidism resolving or Hashimoto’s going into remission have been documented. While complete reversal of advanced autoimmune hypothyroidism is rare based on current evidence, it points to the possibility that thyroid damage may not be permanent and absolute. Some functional medicine practitioners believe supporting thyroid health through diet, lifestyle, and addressing underlying dysfunctions may help recover thyroid functioning in some patients. However, large controlled studies validating these approaches are lacking. For the majority with permanent hypothyroidism, medication remains essential to maintain thyroid hormone levels and health. More research is needed to understand if subgroups of patients are able to regain normal thyroid functioning and the circumstances that facilitate it. While reversals appear rare, they provide hope that perhaps in the future, hypothyroidism could be curable in some cases with a multifaceted and individualized approach.