Hypothyroidism (Underactive Thyroid): A Comprehensive Guide

Posted in , , , by Echelon Health

Understanding the different conditions that can affect your thyroid gland is important, as it can provide you with the knowledge you need to safeguard your health and seek medical support when you need it.

Of the numerous conditions that can impact the health of your thyroid, one of the more common is hypothyroidism – otherwise known as an underactive thyroid.

This comprehensive guide is here to provide you with everything you need to know about this condition, including its various symptoms, causes and treatments. We’ll also look at how you can manage the condition effectively, as well as who is most at risk of it developing. 

What is hypothyroidism?

Hypothyroidism, or an underactive thyroid, affects the small butterfly-shaped gland in your neck (thyroid). It occurs when your thyroid gland does not produce enough of the hormones your body needs.

Since your thyroid helps control your body temperature and is responsible for regulating your metabolism through hormone secretion, when it becomes disrupted, it doesn’t produce enough of the right hormones. This can then cause you to feel unwell.

Fortunately, hypothyroidism can be successfully treated and managed. But, being a lifelong condition, you will need to take treatment throughout the rest of your life as well.

Symptoms of an underactive thyroid

Knowing what symptoms develop with an underactive thyroid is crucial. By understanding what to look for, you’ll know when to seek help from your doctor.

Some of the common symptoms of an underactive thyroid include:

  • Tiredness or fatigue 
  • Weight gain
  • Constipation
  • Depression
  • Muscle aches or weakness
  • Increased sensitivity to the cold
  • Dry skin
  • Brittle nails and hair
  • Decreased libido (sex drive)
  • Pain, numbness or tingling in your hands and fingers
  • Changes to your menstrual cycle such as irregular or heavier periods

As these symptoms can be attributed to other health conditions or environmental factors, it’s a good idea to speak with your doctor so they can rule out or diagnose an underactive thyroid. 

What causes hypothyroidism?

There are many reasons why your thyroid can stop producing enough hormones. Most of the time, the underlying causes are unavoidable and unpreventable.

Some of the main causes of hypothyroidism are:

  • Autoimmune diseases – this is the most common cause of hypothyroidism. Autoimmune diseases occur when your immune system creates antibodies unnecessarily and they attack healthy tissue. Some of these autoimmune diseases impact your thyroid gland, including Hashimoto’s disease.

  • Thyroid surgery – if you have surgery to remove part of your thyroid, this can reduce its ability to produce enough hormones or stop production completely.

  • Thyroiditis – when your thyroid becomes inflamed due to an infection or autoimmune disease, this can lead to a condition called thyroiditis which can cause hypothyroidism.

  • Medication – certain medications or treatments, like radiotherapy, can disrupt your thyroid’s hormone production and cause hypothyroidism.

There are other potential causes of hypothyroidism, but these are much rarer. For example, some women may develop hypothyroidism during pregnancy for unknown reasons.

Other times, it can be caused by a pituitary disorder – a condition where your pituitary gland is unable to produce enough thyroid-stimulating hormone (TSH), leading to decreased hormone production in your thyroid gland and hypothyroidism.

Risk factors for hypothyroidism

Anybody can develop hypothyroidism and it can be present at any age. However, some people do have an elevated risk.

For example, you may be more likely to develop hypothyroidism if you: 

  • Are female
  • Have a family history of thyroid diseases or conditions
  • Already have an autoimmune disease, such as coeliac disease or type 1 diabetes
  • Have previously been treated for hyperthyroidism (overactive thyroid)
  • Have undergone radiation therapy on your neck or upper chest

It’s important to remember that an elevated risk of hypothyroidism does not guarantee the condition and you should always have any symptoms fully investigated by your doctor to confirm their cause.

Diagnosing hypothyroidism

Symptoms of hypothyroidism can vary from person to person, and they can be confused with symptoms of other health conditions. Hypothyroidism doesn’t usually manifest any visual symptoms either, which is why symptoms and a physical examination are not enough on their own to reach a diagnosis.

The most effective and accurate way for hypothyroidism to be diagnosed is with a blood test. This will measure the levels of TSH in your blood as well as check your levels of the thyroid hormone thyroxine (T-4). If the results show your TSH is high and your T-4 is low, you will be diagnosed with hypothyroidism.

Sometimes, your results can show high levels of TSH but normal levels of T-4. If this is the case, you can be diagnosed with subclinical hypothyroidism, which doesn’t usually cause any symptoms.

If you have subclinical hypothyroidism, your condition will need to be monitored as it can develop into hypothyroidism. You may need to have further blood tests every so often as well to check it hasn’t turned into hypothyroidism.

Complications of an underactive thyroid

If left untreated, hypothyroidism can cause complications that can endanger your health. Some of these complications can include: 

  • Goitre – a lump that develops in your throat.

  • Heart problems – low levels of thyroxine can cause increased cholesterol in your blood which can restrict blood flow and cause heart problems.

  • Pregnancy complications – you can be at a higher risk of pre-eclampsia, birth defects, premature birth, miscarriage or stillbirth if hypothyroidism isn’t treated.

  • Myxoedema coma – this is extremely rare but it is a life-threatening complication. When your thyroid hormone levels are dangerously low, you can experience symptoms such as hypothermia and drowsiness.

How is hypothyroidism treated?

Treatment for hypothyroidism is generally treated with hormone replacement tablets called levothyroxine. This will replace the thyroxine your thyroid is not producing and alleviate your symptoms over time. 

Finding the right dosage of levothyroxine can take some time as you will need to start on a lower dosage and work your way up. How high your dosage is depends on how your body responds. Some people may notice an improvement in their health not long after they start taking it. However, other people may not feel changes in their symptoms for several months until the right dosage is reached. 

Once the right dosage of levothyroxine has been found, you will have a blood test once a year to check your thyroid hormone levels. 

If you have subclinical hypothyroidism, you may not be provided with treatment unless you are experiencing or begin to experience symptoms. 

Managing an underactive thyroid

Levothyroxine is the best treatment for an underactive thyroid but you need to follow the prescription instructions very carefully. For example, you will need to take it at the same time every day – usually either first thing in the morning or late at night. 

Food and certain other medications have been shown to reduce levothyroxine’s effectiveness, so you’ll also need to take it on an empty stomach and avoid eating for 30 minutes afterwards. 

Hypothyroidism is a lifelong condition which means you will need to take levothyroxine for the rest of your life. Although you will be taking this medication a lot, it doesn’t usually have any side effects because it’s only replacing the hormones your body needs. Side effects only tend to occur if your dosage is too high. 

You will still need to have a blood test once a year to not only ensure your hormone levels are where they should be while taking levothyroxine but also check whether your dose needs adjusting. 

Book a health assessment at Echelon Health

While hypothyroidism is a fairly common condition, it can be diagnosed and treated easily despite being a lifelong condition. Diagnosing hypothyroidism early can drastically reduce your risk of further complications and help you feel back to normal sooner rather than later. 

Preventative healthcare and early detection are something we champion at Echelon Health which is why we offer a wide variety of health assessment packages, including blood tests for thyroid disorders. 

Learn more about our health assessment packages and book your appointment with our supportive team today. We’ll help you prioritise your overall health and ensure you receive the right referrals for a personalised treatment plan.