How Do You Feel When You Have Hyperthyroidism?

Some people with hyperthyroidism may have no symptoms. When symptoms of hyperthyroidism occur, they may include anxiety, irritability, trouble sleeping, and others.

Hyperthyroidism (also called overactive thyroid) occurs when the thyroid gland in the neck produces too much thyroid hormone and increases the body’s metabolism. 

Hyperthyroidism is not the same as hypothyroidism, which is when a person produces too little thyroid hormone. 

Some people with hyperthyroidism may have no symptoms. When symptoms of hyperthyroidism occur, they may include:

• Anxiety
• Irritability
• Trouble sleeping
• Weakness (especially in the upper arms and thighs, which can make it difficult to lift heavy things or climb stairs)
• Tremors of the hands
• Sweating more than usual
• Heat intolerance
• Fast or uneven heartbeats
• Tiredness/fatigue 
• Weight loss even with a normal or increased appetite 
• Frequent bowel movements 
• Swelling in the neck (goiter)
• Bulging eyes (if hyperthyroidism is caused by Graves' disease)
• Irregular or missed menstrual periods, which may be associated with infertility
• Breast tissue growth in men
• Erectile dysfunction (impotence)
• Atrial fibrillation, chest pain, and rarely, heart failure if untreated

The most common cause of hyperthyroidism is Graves' disease, a condition in which the immune system produces an antibody that stimulates the thyroid gland to produce too much thyroid hormone. 

Other causes of hyperthyroidism include: 

• Thyroid nodules (small growths or lumps in the thyroid gland) that can produce excess thyroid hormone (called a hot nodule, toxic nodule, when there is a single nodule, or, a toxic nodular goiter when there is more than one nodule)
• Painless (“silent or lymphocytic”) thyroiditis, a condition in which the thyroid becomes temporarily inflamed and releases thyroid hormone into the bloodstream
• Postpartum thyroiditis which can occur several months after delivery can cause the thyroid to become temporarily inflamed and release thyroid hormone into the bloodstream
• Subacute (granulomatous) thyroiditis which is believed to be caused by a virus
• Taking too much thyroid hormone medication for hypothyroidism which can increase thyroid blood levels 

Hyperthyroidism is diagnosed with blood tests that measure the amount of thyroid hormone and thyroid-stimulating hormone (TSH). 

Other tests may include: 

• Thyroid scan 
• A blood test to help determine the cause of hyperthyroidism (such as Graves' disease, toxic nodular goiter, or thyroiditis)

Hyperthyroidism is treated with medications, radioiodine, or surgery. 

Medications used to treat hyperthyroidism include: 

• Antithyroid drugs that work by decreasing how much thyroid hormone the body makes
  • Methimazole (MMI or Tapazole) 
  • Propylthiouracil (PTU)
• Beta-blockers to help control symptoms of hyperthyroidism such as rapid heart rate, tremors, anxiety, and heat intolerance
  • Atenolol (Tenormin)
  • Propranolol (Inderal)

Radioactive iodine is used to destroy the thyroid with radioiodine in a process called ablation.

• The most widely used treatment for hyperthyroidism in the U.S.
• A permanent way to treat hyperthyroidism
• The dose of radiation used is small and does not cause cancer, infertility, or birth defects

Surgery is indicated in certain cases:

• A large goiter blocks the airways, causing difficulty breathing
• The patient is unable to tolerate antithyroid drugs and does not want to use radioiodine
• A nodule in the thyroid gland could be cancer
• Active Graves' eye disease