What Is Hyperthyroidism?
Hyperthyroidism is a condition where the thyroid gland produces too much thyroid hormone. These hormones—T3 (triiodothyronine) and T4 (thyroxine)—regulate your body’s metabolism. When there is an excess, your metabolism speeds up, which can affect many body systems and lead to various symptoms.
What Causes Hyperthyroidism?
The most common causes of hyperthyroidism include:
- Graves’ disease – an autoimmune disorder where the immune system stimulates the thyroid to produce too much hormone
- Thyroid nodules – lumps in the thyroid that produce excess hormones
- Thyroiditis – inflammation of the thyroid, sometimes caused by infection or autoimmune conditions
- Excessive iodine intake
- Overmedication with thyroid hormone (in those treated for hypothyroidism)
What Are the Symptoms?
Symptoms of hyperthyroidism can vary but often include:
- Unintentional weight loss
- Rapid heartbeat (tachycardia)
- Increased appetite
- Nervousness, anxiety, or irritability
- Tremors, usually in the hands or fingers
- Sweating and heat intolerance
- Frequent bowel movements
- Fatigue or muscle weakness
- Difficulty sleeping
- Hair thinning or brittle hair
- In women: irregular or lighter menstrual cycles
- In Graves’ disease: bulging eyes (exophthalmos)
How Is It Diagnosed?
Diagnosis typically involves:
- Blood tests:
- TSH (thyroid-stimulating hormone) – usually low
- Free T4 and T3 – usually high
- Thyroid antibody tests – to check for Graves’ disease
- Radioactive iodine uptake test – to assess thyroid activity
- Thyroid scan – to detect nodules or inflammation
What Is the Treatment?
Treatment options depend on the cause, severity, and patient preference. Common treatments include:
- Antithyroid medications (e.g., methimazole, propylthiouracil) – to reduce hormone production
- Beta-blockers – to control symptoms like rapid heart rate and tremors
- Radioactive iodine therapy – destroys overactive thyroid tissue
- Surgery (thyroidectomy) – removal of all or part of the thyroid gland, usually for large goiters or when other treatments fail
Are There Any Complications?
If left untreated, hyperthyroidism can lead to:
- Heart problems (e.g., atrial fibrillation, heart failure)
- Osteoporosis
- Thyroid storm – a rare, life-threatening condition where symptoms become severe
- Eye problems – especially with Graves’ disease
- Fertility issues in women
What Is the Outlook?
Most people with hyperthyroidism can manage the condition effectively with treatment. Depending on the approach, some may become hypothyroid afterward and require lifelong thyroid hormone replacement therapy. Regular monitoring is important to ensure hormone levels stay balanced.
Can Hyperthyroidism Be Prevented?
There is no guaranteed way to prevent hyperthyroidism, especially if it is caused by autoimmune conditions. However, you can:
- Limit iodine intake if advised by your doctor
- Regularly monitor thyroid function if you have a family history or other risk factors
- Avoid overuse of supplements or medications containing iodine