How Do Thyroid Disorders Contribute To Sweating And An Increased Sensation Of Heat

A summer heat and the winter breeze. We may associate the seasons with these changes in temperature and response, swap out our clothing and alter our lifestyle to manage these changes. That seems like a normal task to undertake during certain points of the year. However, some individuals, regardless of the season, may struggle all year around to regulate their body temperature. In this article, we will explore the role the thyroid gland plays in regulating our body temperature and what happens when this goes wrong.

Introduction to the thyroid gland

What is the thyroid gland?

The thyroid gland is a butterfly-shaped structure located at the front of the neck, just below the voice box. The thyroid gland is made up of many follicles, which can secrete hormones. These hormones are crucial for normal growth and development in mammals, and therefore, abnormalities in the amount of circulating hormones are linked to a range of ailments, including heat intolerance. The effects of a thyroid hormone deficiency can become most obvious during pregnancy in which infants may not grow at the expected rates and show signs of developmental delays.¹

The thyroid gland produces 2 hormones, tri-iodothyronine (T3) and thyroxine (T4), which are released into the blood. Iodine is a very important mineral that is needed to make these hormones; therefore, iodine supplements may be recommended for breastfeeding and pregnant individuals. The release of these hormones is very tightly regulated in a feedback cycle with another hormone, TSH, which is found in the brain. This ensures that the appropriate amount of hormones are released into our circulation. However, sometimes this feedback cycle can become broken, which can lead to thyroid disorders. One consequence of having a thyroid disorder is having an increased sensation of heat.

What are the actions of the thyroid hormones?

Hormones are chemical messengers that circulate in our blood and can control and regulate many of our body's actions at the whole body, cellular, and molecular levels. Hormones are released into the blood by many different organs. What distinguishes the actions of the thyroid hormones compared to other hormones is their specificity to attach to specific cells. 

All cells have receptors that can recognise many different chemicals, including hormones. In our body, the receptors that recognise thyroid hormones are found all over the body, including our bone, skeletal and cardiac muscle, brain, and kidney.³ This means that the actions of thyroid hormones can be very diverse.

Once in our cells, these thyroid hormones can control the activity of certain genes to influence a range of biological outcomes, including: 

• Metabolism:the ability for our body to convert food into energy is known as metabolism. The thyroid hormones help to activate genes that can utilise fat stores, store glucose, and break down carbohydrates and proteins
• Heat production:as a result of an increased metabolism, the thyroid hormones can help aid heat production. This process involves the burning of fat to create thermal energy. This process burns calories, therefore, the thyroid hormones can influence our weight too
• Growth and development:the thyroid hormones help with normal skeletal growth, effective healing of fractures and regulating bone mass - important for having strong bones.² The thyroid hormones can work with growth hormones during childhood to stimulate bone growth.⁴ The thyroid hormones also can stimulate the nervous system and are essential for normal brain development.⁵ This can range from our mood, our ability to be mobile and our memory; therefore, regulation of thyroid hormones is important throughout life
• Cardiovascular function: the thyroid hormones can also influence the activity of the heart, including increasing heart rate and cardiac output which ensures all parts of our body can access oxygen and nutrients. The thyroid hormones can also dilate our blood vessels which can help to regulate temperature

Overview of thyroid disorders

What is hypothyroidism? 

Hypothyroidism occurs when the body is unable to produce enough of the thyroid hormones. Causes of hypothyroidism include having low levels of iodine in the diet, which prevents sufficient amounts of the thyroid hormones from being made. 

One of the most common causes of hypothyroidism is an autoimmune response in which the body produces antibodies that attack the cells in the thyroid, and this is known as Hashimato’s disease. Sometimes, babies may be born with hypothyroidism, which is known as congenital hypothyroidism.

Regardless of the cause of hypothyroidism, if appropriate amounts of the thyroid hormone are not produced, then they cannot enter cells and establish their effects. As the thyroid hormones act on the body in many different ways, having hypothyroidism can lead to a range of symptoms and ailments. Therefore, hypothyroidism must be recognised and treated appropriately. 

At a doctor's appointment, a slow pulse and blood tests revealing low levels of T3 and T4 can help to confirm a diagnosis. Hypothyroidism can be treated by medicating individuals with levothyroxine, an artificial version of T4 (thyroxine). Medicating with levothyroxine requires carefully measured doses, as taking too much of the medicine can lead to hyperthyroidism.

What is hyperthyroidism?

Hyperthyroidism occurs when the thyroid gland produces too many thyroid hormones. This could be a result of an autoimmune disease in which antibodies can activate thyroid hormone production. Other causes of hyperthyroidism can include thyroid tumours, which can over-activate the thyroid gland, and after pregnancy, inflammation of the thyroid can lead to the temporary condition of postpartum thyroiditis. One of the physical signs of hyperthyroidism is having a swollen gland or lump in the neck, also known as goitre.

A diagnosis of hyperthyroidism can be made by recording physical symptoms of the disorder alongside blood tests that reveal elevated levels of TSH. Antithyroid drugs can be prescribed to treat individuals with hyperthyroidism. Surgery to remove part of the thyroid gland can also be performed to treat Graves’ disease and can be an alternative treatment for those unable to take medicines. 

How do thyroid disorders alter our heat sensation? 

What are the effects of hyperthyroidism on the body?

Having an overactive thyroid gland can have numerous effects on the body. Physically, a goitre may be seen on the neck and individuals may experience weight loss due to having an increased metabolism. 

As there are too many thyroid hormones circulating in the body, some individuals may have an irregular heartbeat and feel heart palpitations. This can make exercising difficult and can increase the risk of getting a cardiovascular disease by 16%.⁶

People with hyperthyroidism can experience excess sweating, usually at the palms and soles of the feet. As the heart activity increases, so does the blood flow around the body and towards the skin's surface. This makes the skin warm and moist to the touch and can result in individuals sweating more frequently and generally feeling warm and uncomfortable. Whilst the exact reasoning behind excess sweating is unknown, it's thought that the thyroid hormones can work synergistically with hormones involved in our fight or flight response, and that contributes to excess sweating.⁷ 

What are the effects of hypothyroidism on the body?

As the thyroid gland is underactive, individuals with hypothyroidism will experience a slow metabolism. This may manifest in the form of weight gain, despite having no change in diet/appetite, as the body is unable to utilise fat into energy so it becomes stored instead. Because of the lack of energy released from fat, people may feel tired more easily. 

Individuals with hypothyroidism may also become more sensitive to the cold and can also have cold skin to the touch. As their metabolism is slower, the person’s body is unable to generate heat from burning fat and their blood vessels constrict instead of dilating to try and retain heat. This can lead to their hands, feet and other extremities (ears, nose tips) feeling cold as there is a focus to conserve heat to the core of the body. 

As a result of taking too much levothyroxine medication, individuals with hypothyroidism can experience sweating problems. This sweating stems from the reasons of hyperthyroidism. 

How to manage an increased sensation of heat?

For those experiencing sweating issues related to a thyroid disorder, there can be ways to manage sweating whilst the medication takes its effect.

Night sweating may be a common occurrence which can be managed by sleeping in a cool bedroom, using a fan or air conditioning if possible and wearing loose clothing to sleep. 

Choosing breathable clothing to wear can help the sweat evaporate from the body instead of sticking to the skin and contributing to the feeling of discomfort. Try looking for natural fabrics, such as cotton and linen, that are lightweight and allow air to flow around the body. 

For quick comfort, keeping a glass of water nearby and flipping the pillow to the cold side may help you to cool down quickly in the middle of the night.

Summary

The thyroid gland is an important organ that regulates many biological processes. Without it, we would not be able to grow and develop normally, utilise energy stores efficiently and have our heart beat appropriately. 

The thyroid hormones (T3 and T4) released from the thyroid gland are central in controlling these processes. If there are too many or too little of these hormones, this can greatly disrupt the inner workings of our body. 

One way that these thyroid disorders can manifest is through an altered heat sensation. Individuals with hypothyroidism may be unable to withstand the cold, whilst those with hyperthyroidism may experience excess sweating. These experiences can feel uncomfortable and maybe a little embarrassing. Luckily, there are many available treatments for thyroid disorders and different strategies can be used to try and manage the body temperature.