Hyperthyroidism
Hyperthyroidism is a syndrome defined by excess thyroid hormone production by the thyroid gland. It is distinct from but related to thyrotoxicosis, which refers to excess thyroid hormone exposure to tissues (a state that can arise from hyperthyroidism or other mechanisms such as ingestion of exogenous thyroid hormone or release from a damaged gland).
Causes
- graves-disease — the most common cause in the United States (~80% of cases); an autoimmune condition in which TSH-receptor antibodies stimulate the thyroid to overproduce hormone.
- Toxic multinodular goitre
- Toxic adenoma
- iodine-induced-hyperthyroidism — caused by excessive iodine intake via supplements, iodized salt, seaweed/kelp, or iodine contrast dyes; usually temporary but can require dietary or medical intervention.
- Excessive exogenous thyroid hormone
Symptoms
Symptoms result from the metabolic acceleration caused by excess thyroid-hormones:
- Unintentional weight loss
- Anxiety, nervousness
- Palpitations and elevated heart rate
- Tremors
- Sweating
- Frequent bowel movements
- Difficulty sleeping / insomnia
- Muscle weakness
- Decreased bone-mineral-density with chronic untreated disease (leading to osteoporosis)
Hyperthyroidism is more common in females than males.
Dietary Management
Diet cannot cure hyperthyroidism but can help manage symptoms and prevent complications. For a detailed breakdown see:
- low-iodine-diet
- selenium (supports thyroid function and may reduce autoimmune activity)
- calcium and vitamin-d (protect bone density)
- zinc (deficiency linked to Graves’ disease)
- cruciferous-vegetables (may reduce hormone production and iodine uptake)
- anti-inflammatory-diet
Foods to limit or avoid:
- Excessive iodine (worsens autoimmune hyperthyroidism)
- Caffeine (amplifies symptoms)
- soy (interferes with radioactive-iodine-treatment)
- Gluten (possible link to Graves’ disease worsening; evidence limited)
- kelp (very high iodine content)
Medical Treatment
- Antithyroid medications (e.g., methimazole, propylthiouracil) — reduce thyroid hormone synthesis
- radioactive-iodine-treatment — destroys overactive thyroid tissue
- Thyroid surgery — for structural causes or treatment failures
- Supplements such as carnitine and selenium have shown benefit for specific symptoms in clinical trials.