Hypothyroidism: Causes, Symptoms, Diagnosis & Treatment
Hypothyroidism is a common condition in which the thyroid gland does not produce enough hormones to meet the body’s needs. These hormones play a key role in regulating metabolism, energy levels and the function of most organs. When levels drop, the body slows down, often leading to fatigue, weight gain and other health concerns.
Although the condition can develop gradually, early diagnosis and appropriate treatment allow most patients to live a normal, healthy life.
What Is Hypothyroidism?
The thyroid is a small gland located at the front of the neck. Despite its size, it plays a crucial role in maintaining the body’s balance. It produces two essential hormones – triiodothyronine (T3) and thyroxine (T4) – which regulate how the body uses energy.
The thyroid works closely with the pituitary gland, which releases thyroid-stimulating hormone (TSH). This system ensures that hormone levels remain stable. When this balance is disrupted, hypothyroidism can develop.
How Common Is Hypothyroidism?
Hypothyroidism affects around 1–6% of the population and is significantly more common in women than in men. The risk increases with age, particularly after the age of 60. However, it is not limited to older adults — younger individuals and even children can also be affected.
In many cases, there is a genetic component, meaning people with a family history of thyroid disorders should be particularly aware of potential symptoms.
What Causes Hypothyroidism?
The most common cause of hypothyroidism is Hashimoto’s disease, an autoimmune condition in which the immune system mistakenly attacks the thyroid gland. Over time, this leads to inflammation and reduced hormone production.
Other causes, although less common, include thyroid disorders related to thyroid surgery, radiotherapy to the neck, radioactive iodine treatment and certain medications. In some cases, iodine imbalance or genetic factors may also contribute.
What Are the Symptoms of Hypothyroidism?
The symptoms of hypothyroidism often develop slowly, which means they can easily be overlooked in the early stages. Many people initially attribute them to stress or ageing.
Common symptoms include persistent tiredness, feeling unusually cold and unexplained weight gain. Some individuals also experience low mood, memory problems or difficulty concentrating.
Physical changes are also typical. The skin may become dry and pale, while hair can thin or lose its shine. Digestive issues such as constipation and cardiovascular symptoms like a slow heart rate may also occur. In women, menstrual irregularities and difficulty conceiving are not uncommon.
If left untreated, symptoms can gradually worsen and may lead to more serious complications.
Why Early Diagnosis Is Important
Although hypothyroidism is usually manageable, untreated cases can lead to significant health problems. These include high cholesterol, heart disease and infertility. In rare but severe cases, it can result in a life-threatening condition known as myxoedema coma.
For this reason, recognising symptoms early and seeking medical advice is essential.
When Should You See a Doctor?
Anyone experiencing symptoms suggestive of hypothyroidism should consult a GP or endocrinologist. A simple thyroid diagnostic assessment and blood test can often provide a clear indication of thyroid function.
Testing is particularly important for individuals with a family history of thyroid disease or those with autoimmune conditions such as type 1 diabetes, coeliac disease, vitiligo or psoriasis.
How Is Hypothyroidism Diagnosed?
Diagnosis is primarily based on thyroid blood tests, which measure hormone levels and assess overall thyroid function. The first step is usually measuring TSH levels through a comprehensive blood test. If TSH is elevated, further testing is carried out to assess free thyroxine (FT4).
Hypothyroidism is typically confirmed when TSH levels are high and FT4 levels are low. In suspected autoimmune cases, additional tests such as anti-TPO and anti-Tg antibodies may be recommended.
The Role of Thyroid Ultrasound
A thyroid ultrasound scan is often used to support the diagnosis. It can reveal characteristic changes associated with autoimmune thyroid disease and help identify nodules or structural abnormalities that may require further evaluation.
Treatment of Hypothyroidism
Treatment involves thyroid treatment aimed at replacing the hormones that the thyroid is no longer able to produce. The standard therapy is Levothyroxine, a synthetic hormone that mimics the action of natural thyroxine.
With correct use, levothyroxine helps restore normal hormone levels, improve symptoms and prevent long-term complications. Most patients can be managed without hospitalisation.
How to Take Levothyroxine Correctly
For treatment to be effective, levothyroxine must be taken consistently. It is usually recommended to take the medication in the morning, on an empty stomach, around 30 to 60 minutes before eating.
Patients should take it at the same time each day and avoid combining it with certain supplements, such as iron or calcium, which may affect absorption.
Regular blood tests are required, especially in the early stages of treatment, to ensure the dosage is correct.
Monitoring and Long-Term Management
During the initial phase of treatment, thyroid levels are typically checked every 6 to 12 weeks. Once stabilised, monitoring is usually reduced to once or twice a year.
In most cases, hypothyroidism requires lifelong treatment. However, in certain situations, such as temporary thyroid inflammation or medication-related cases, thyroid function may recover.
Hypothyroidism in Children
In children, hypothyroidism is particularly serious as it can affect growth and brain development. Congenital hypothyroidism, present at birth, requires early detection and treatment to prevent long-term complications.
For this reason, newborn screening programmes are used to identify the condition shortly after birth.
Hypothyroidism and Pregnancy
Thyroid hormones are especially important during pregnancy. Untreated hypothyroidism can affect fertility, increase the risk of miscarriage and lead to complications during pregnancy.
Women who are planning a pregnancy or are already pregnant should have their thyroid function monitored closely. In many cases, the dose of levothyroxine needs to be increased to meet the body’s higher demands.
Iodine and Thyroid Health
Iodine is essential for thyroid hormone production. Adults typically require around 150 micrograms per day, while pregnant women need approximately 250 micrograms.
Good dietary sources include iodised salt, fish, dairy products and eggs. In some cases, supplements may be recommended.
Diet, Supplements and Lifestyle
Many patients wonder whether dietary changes or supplements can improve thyroid function. At present, there is limited scientific evidence to support the routine use of supplements such as selenium.
A balanced diet and healthy lifestyle remain important, but any specific dietary changes should be guided by a healthcare professional.
Living With Hypothyroidism
Hypothyroidism is often influenced by genetic factors, meaning it cannot always be prevented. However, with proper treatment and regular monitoring, it can be effectively controlled.
Most patients are able to maintain a normal lifestyle, free from significant symptoms, as long as they follow medical advice and attend regular check-ups.
Private Thyroid Testing and Consultation
If you are experiencing symptoms of hypothyroidism or want a professional assessment, Pax Medicus offers private thyroid diagnostics, access to thyroid treatment and the option to book a consultation without long waiting times.