What is Hyperthyroidism?

Caused by an overactive thyroid, hyperthyroidism happens when too much of the thyroid hormone is produced, leading to some unpleasant symptoms. It’s worth knowing that while it’s rare in all individuals, Hyperthyroidism is much more common in women than men. In this post, we’re going to look at some of the common hyperthyroidism symptoms, as well as causes and treatments for the condition. We’ll also reveal how tracking your menstrual cycle can help you get to know your body better and keep track of symptoms.

Illustration of the head and shoulders of a woman showing where the thyroid gland is in the centre of the throat

The thyroid gland

Located in the lower front of the throat, the thyroid gland is shaped like a butterfly. This important gland’s main function is to produce the thyroid hormone, which is carried through the blood to different tissues throughout our bodies. The thyroid hormone plays a lot of important roles, affecting heart rate, and regulating our body temperature. If the gland doesn’t produce the right amount of hormone, it can lead to an underactive thyroid, also known as hypothyroidism, but we’re going to cover an overactive thyroid, also known as hyperthyroidism.

Hyperthyroidism symptoms

There are a number of signs and symptoms of hyperthyroidism. These may develop over time or appear suddenly. Not everyone is likely to experience all symptoms and these signs may also vary in severity from person to person. It’s also worth remembering that hyperthyroidism is a rare condition and symptoms may be a sign of another condition. If you have any concerns or have noticed any changes in your body then it’s always a good idea to speak to your doctor. Some common hyperthyroidism symptoms are:

  • Changes to mood such as nervousness, anxiety, and irritability
  • Increased energy or feeling unable to sit still
  • Mood swings
  • Sensitivity to heat, having warm skin, or excessive sweating
  • Insomnia
  • Exhaustion
  • Diarrhea
  • Needing to pee more often
  • Extreme thirst
  • Itchiness
  • Loss of libido (sex drive)
  • Swelling in the neck
  • Unusually high or irregular heart rate
  • Red palms
  • Loose finger and/or toenails
  • Hives (a raised itchy rash)
  • Weight Loss (often with an increased appetite)
  • Problems with vision and/or irritated eyes

Hyperthyroidism causes

Below we’ll outline some of the common (and not so common) causes of hyperthyroidism. Of course, if you are experiencing any symptoms or have concerns about your health, you should consult with your doctor as soon as you can. Hyperthyroidism causes include:

Graves' disease - this is the most common cause of an overactive thyroid. It’s estimated that three out of four people with hyperthyroidism also have Graves' disease. This autoimmune disease is most common in younger and middle-aged women. Graves' disease causes hyperthyroidism when the immune system mistakenly attacks the thyroid gland causing it to produce too much thyroid hormone. The cause of Graves' disease is unknown, but it tends to run in families.

Thyroid nodules - a less common cause of hyperthyroidism, thyroid nodules are non-cancerous lumps that form on the gland. If the nodules contain thyroid tissue it can cause the thyroid gland to become overactive. Thyroid nodules are most common in women over 60 and the cause is also unknown. 

Medication - some medicines that contain iodine can cause the thyroid gland to become overactive. Your levels of thyroid hormone are likely to return to normal after your stop taking the medication, but it may take several months to become stable again. 

Human chorionic gonadotropin - high levels of this substance can lead to an overactive thyroid gland during early pregnancy. 

Benign pituitary tumors - a non-cancerous growth on the pituitary gland can also lead to hyperthyroidism.

Thyroiditis - a swelling of the thyroid gland itself can cause excess thyroid hormone to be produced and can cause an overactive thyroid.

Thyroid cancer - in rare cases a cancerous tumour on the thyroid gland can also cause hyperthyroidism. 

Hyperthyroidism treatment

A simple blood test is usually required to check levels of thyroid hormone in the blood, and give a diagnosis of hyperthyroidism. There are a number of treatments available, these are:

Medication - thioamides are given to stop the thyroid gland from producing extra thyroid hormone. It can take one or two months before you may notice a difference, and other medications such as beta-blockers are often given in the meantime. Medication is taken until the thyroid production returns to normal, but in some cases, it might be necessary to continue to take thioamides longer term or for life. 

Radioactive iodine treatment - another way to cure hyperthyroidism is through radioactive iodine treatment. This comes in the form of an iodine capsule and a low dose of radiotherapy, which destroys cells in the thyroid gland. Most people only need one treatment, but it can take several weeks before the results are felt. It’s not suitable for women who are pregnant or breastfeeding.

Surgery - in rarer cases surgery to remove part or all of the thyroid gland may be recommended. This is usually only an option if either medication or radioactive iodine treatments aren’t possible. If the entire thyroid gland is removed it will be necessary to take medication for an underactive thyroid to counteract the lack of thyroid hormone production. 

Hyperthyroidism in women

Anyone at any age can get an overactive thyroid. However, hyperthyroidism is ten times more common in women than in men. It’s also most common in women between the ages of 20 to 40 years old. 

Hyperthyroidism also has a link to the menstrual cycle, in that it affects our body temperature, which naturally changes throughout our cycles. Manual tracking of basal body temperature can be more difficult for women who have a thyroid condition since it can be harder to identify when ovulation has happened due to frequent changes in temperature throughout the cycle. However, it’s by no means impossible, thanks to some incredible science…

Understanding your body better

Natural Cycles is an app paired with a basal thermometer that helps you track your ovulation and find your fertile window. Since the app learns your unique cycle many women choose to use it, not only as a birth control method, but to get to know their body better and spot any changes that are happening. Why not find out if Natural Cycles could work for you?

Are you ready to learn your unique cycle?

Jen on the roof terrace at Natural Cycles headquarters.

Written By

Jennifer Gray

A writer with a passion for women’s health, Jennifer Gray has years of experience writing about various reproductive health topics including birth control, planning pregnancy, women’s anatomy, and so much more.

Jack in a suit and tie holding a microphone and giving a presentation.

Scientifically Reviewed

Jack Pearson

With 10 years of experience working in the field of fertility, Jack Pearson is Natural Cycles’ in-house expert. As Medical Affairs Manager, he dedicates his time to conducting groundbreaking research and educating healthcare professionals.