Thyroid issues can be genuinely difficult to identify, since symptoms are often subtle and easily mistaken for the general effects of a busy modern life. As a result, many people live with an undiagnosed thyroid condition for years without realising it.
The thyroid is a gland located in the throat, near the windpipe, responsible for releasing two key hormones: triiodothyronine (T3) and thyroxine (T4). These hormones play an essential role in keeping the body's organs functioning properly.
Sometimes the thyroid doesn't function as it should. Thyroid conditions are relatively common, and notably more common in women than men, with some hereditary component as well.
The two most common thyroid conditions are hyperthyroidism (an overactive thyroid) and hypothyroidism (an underactive thyroid). These typically develop in adulthood, most often between ages 20 and 40, though they can occur at any age, including in newborns – which is why babies are routinely screened shortly after birth, since untreated hypothyroidism in infancy can affect physical and developmental progress.
Symptoms and Impact of Hyperthyroidism
An overactive thyroid releases excess amounts of T3 and T4, which can cause a range of symptoms, including:
- Restlessness, anxiety or irritability
- Muscle tremors
- A swollen or enlarged neck
- Heart palpitations or a raised resting heart rate
- Increased sensitivity to heat
- Sudden, unexplained weight loss
If you're experiencing these symptoms, it's worth speaking to your GP about a blood test, which will typically identify elevated hormone levels if hyperthyroidism is present. Further testing may follow depending on the suspected cause, and treatment will vary accordingly. If you'd like an initial indication before seeing your GP, our thyroid self-test can offer a useful starting point.
Causes and Treatment for Hyperthyroidism
Graves' disease, an autoimmune condition where the immune system mistakenly attacks the thyroid gland, is the most common cause of hyperthyroidism. It can also occur as a side effect of certain medications, or as a result of nodules on the thyroid gland.
If caught early and managed appropriately, hyperthyroidism doesn't need to be a major long-term concern. Treatment often starts with thionamides – medications such as propylthiouracil or carbimazole that reduce hormone production. Depending on the underlying cause and how the condition responds, some people complete a defined course of treatment, while others may need longer-term management.
Where medication isn't sufficient, further options include surgery to remove part of the thyroid gland, or radioiodine treatment, which reduces the gland's hormone-producing capacity. Your doctor will talk through the right option for your specific situation – once under control, hyperthyroidism doesn't typically prevent a full, active life.
Symptoms and Impact of Hypothyroidism
Hypothyroidism occurs when the thyroid doesn't produce enough T3 and T4. It develops gradually rather than causing sudden illness, which is part of why it can go unnoticed for some time. Common symptoms include:
- Persistent tiredness
- Aching muscles and limbs, particularly in the legs
- Increased sensitivity to cold
- Dry or flaky skin and hair
- Low mood
- Weight gain, or difficulty losing weight despite diet and exercise
Unexplained weight changes are often what first prompt people to investigate hypothyroidism. Many GPs will also consider a thyroid blood test for patients presenting with depression, given the increasingly recognised link between thyroid function and mental health.
Causes and Treatment for Hypothyroidism
Hypothyroidism is often hereditary, with increased likelihood if a parent has the condition. It can also result from the thyroid gland being affected by illness, or develop later in some people previously treated for hyperthyroidism.
Treatment is generally straightforward – a once-daily tablet called Levothyroxine, which supplements the body's hormone levels. Finding the right dosage can take some trial and error, typically involving several blood tests over the first 6-12 months after diagnosis.
With consistent treatment, hypothyroidism doesn't prevent a full and active life, though it does require lifelong medication and periodic monitoring to keep dosage correctly balanced.
When to Take Thyroid Concerns Seriously
Most thyroid issues come down to hyper- or hypothyroidism, but occasionally the underlying cause can be more serious, such as a pituitary problem or, rarely, a tumour. This is exactly why it's worth raising any suspected thyroid issue with a healthcare professional promptly rather than waiting – early investigation generally means simpler treatment. You can also learn more about thyroid function and testing on our thyroid health page.
