What Is Hyperthyroidism (Overactive Thyroid)?

Your thyroid is a small gland located in your neck. Hyperthyroidism is a condition in which your thyroid becomes overactive and secretes too much of the thyroid hormone, thyroxine.


Women who have hyperthyroidism may experience: 

  • Abnormal menstrual cycles (shorter, longer, heavier or lighter than average)
  • Rapid or irregular heartbeat, double vision and muscle weakness
  • Feeling shaky or extra nervous
  • Weight loss, diarrhea and increased appetite
  • Thin skin, sweatiness and inability to handle heat 
  • Neck swelling due to an enlarged thyroid gland and/or bulging eyes (from Graves’ disease)


Women are more likely than men to develop hyperthyroidism. Also, a number of different medical conditions can cause the condition. Common hyperthyroidism causes are:

  • Graves’ disease: More than 70 percent of women who have hyperthyroidism have this condition. Graves’ disease occurs when antibodies in the blood “fight” the thyroid gland and cause it to overproduce hormones.
  • Noncancerous growths: When small nodules (noncancerous tumors) grow on the thyroid, they can cause the gland to release more hormones than usual into the bloodstream. 
  • Thyroiditis: This condition can occur when a virus or immune system issue prompts the thyroid gland to swell and release too many of its stored hormones.

Hyperthyroidism tends to be genetic, which means it can run in families. More women than men develop this condition.

  • You may also have an increased chance of developing hyperthyroidism if you:
  • Are pregnant or have given birth in the last six months
  • Are age 60 or older
  • Have Type 1 diabetes
  • Consume too much iodine in your diet (through food, medication or supplements)


The simplest way for your doctor, nurse practitioner or midwife to diagnose hyperthyroidism is with a full physical exam and a blood test. If you have hyperthyroidism, your T3 and T4 hormone levels will be higher than usual and your thyroid-stimulating hormone (TSH) will be lower than normal.

Your practitioner can also order an ultrasound exam of your thyroid. Ultrasounds are painless procedures that use sound waves to create images of your thyroid. The images allow your doctor to check and see whether any growths have developed on the gland. 


Depending on your symptoms, your primary care provider may refer you to an endocrinologist. This medical professional specializes in treating individuals with hormonal disorders. 

Your primary care provider or endocrinologist may suggest a range of different treatment options. They will choose the overactive thyroid treatment that’s right for you based on your age, the severity of your symptoms and whether you have other health conditions.

Common hyperthyroidism treatment options include:

  • Anti-thyroid medications: These drugs block your thyroid from producing extra hormones.
  • Radioactive iodine: This simple treatment involves swallowing a small pill filled with radioactive iodine, a mineral that’s been specially treated for this purpose. The iodine kills abnormal cells in your thyroid. Some patients need a second treatment. Afterward, you may need to take a daily supplement to replace the hormones your thyroid can no longer create.
  • Surgical treatment: In some cases, a specialized thyroid surgeon may remove your thyroid gland (thyroidectomy). If you’re pregnant or can’t tolerate the thyroid medications or radioactive iodine, you may be a good candidate for surgery. You’ll need to take a thyroid supplement every day for the rest of your life.
  • Beta blockers: These drugs won’t cure hyperthyroidism, but they can improve your uncomfortable symptoms within hours or days. Beta blockers are particularly effective at slowing down a rapid heartbeat and decreasing shakiness. Your doctor may prescribe beta blockers along with any of the other treatment options.


It’s important to see a doctor if you have symptoms that indicate you might have an overactive thyroid. If you leave it untreated, hyperthyroidism can lead to health complications that include:

  • Heart problems: The greatest risks related to hyperthyroidism are heart rhythm and circulation-related problems. Fortunately, these heart conditions tend to improve or disappear completely when you get treatment for the underlying hyperthyroidism.
  • Weak bones: Hormones from your thyroid can affect bone strength and lead to osteoporosis. This condition causes women to develop weak, brittle bones.
  • Eye and vision problems: People who have Graves’ disease (the leading cause of hyperthyroidism) may develop painful eye problems that can lead to permanent vision loss if left untreated.
  • Skin problems: It’s fairly rare, but people who have Graves’ disease can experience red, swollen legs and feet.

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