Hyperthyroidism (also called overactive thyroid) occurs when the thyroid gland in the neck produces too much thyroid hormone and increases the body’s metabolism. Thyroid disease occurs more often in women than in men.
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 they do occur, symptoms of hyperthyroidism in both females and males may include:
- Anxiety
- Nervousness
- Irritability
- Unexplained weight loss
- Fast or uneven heartbeats
- Trouble sleeping (insomnia)
- Weakness (especially in the upper arms and thighs, which can make it difficult to lift heavy things or climb stairs)
- Tremors of the hands
- Increased sweating
- Heat sensitivity or intolerance
- Tiredness/fatigue
- Increased appetite
- Frequent bowel movements/changes in bowel movements
- Swelling in the neck due to enlarged thyroid gland (goiter)
- Bulging eyes (if hyperthyroidism is caused by Graves' disease)
- Breast tissue growth in men
- Erectile dysfunction (impotence)
- Atrial fibrillation, chest pain, and rarely, heart failure if untreated
- Increased risk of osteoporosis
- In patients who have Graves’ disease:
Symptoms of hyperthyroidism in females also include:
- Changes in menstrual periods, such as lighter flow
- Less frequent periods
- Missed menstrual periods
- Infertility
- Hot flashes
- Mood swings
What Causes Hyperthyroidism?
Graves' disease, a condition in which the immune system produces an antibody that stimulates the thyroid gland to produce too much thyroid hormone, is the most common cause of hyperthyroidism.
Other causes of hyperthyroidism include:
- Thyroid nodules (small growths or lumps in the thyroid gland)
- 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
- Subacute (granulomatous) thyroiditis, thought to be caused by a virus
- Taking excess thyroid hormone medication for hypothyroidism
- Consuming foods or medicines that contain high levels of iodine
How Is Hyperthyroidism Diagnosed?
Hyperthyroidism is diagnosed with blood tests that measure the amount of thyroid hormone and thyroid-stimulating hormone (TSH).
Other tests may include:
- Thyroid scan
- Blood test to help determine the cause of hyperthyroidism (such as Graves' disease, toxic nodular goiter, or thyroiditis)
How Is Hyperthyroidism Treated?
Treatment for hyperthyroidism includes:
- Medications
- Antithyroid drugs
- Methimazole (MMI or Tapazole)
- Propylthiouracil (PTU)
- Antithyroid drugs
- Beta-blockers
- Atenolol (Tenormin)
- Propranolol (Inderal)
- Radioactive iodine
- Used to destroy the thyroid in a process called ablation
- The most widely used treatment for hyperthyroidism in the U.S.
- A permanent treatment
- The dose of radiation used is small and does not cause cancer, infertility, or birth defects
- Surgery in some cases
From 
https://familydoctor.org/condition/hyperthyroidism/
https://www.hopkinsmedicine.org/health/conditions-and-diseases/thyroid-disorders-in-women