The Thyroid: A Small Gland with a Big Impact

By Dr. Gabriel Grabowski, specialist in internal medicine and pulmonology

The thyroid is a small, butterfly-shaped gland at the front of the neck. Its hormones help regulate how the body uses energy, influencing heart rate, digestion, temperature and concentration. When hormone production changes, the effects may be felt in several parts of the body.

I often see symptoms in my practice that could have several explanations: tiredness, a change in weight or a faster heartbeat. The thyroid is one possibility, but not the only one. Particularly after 50, it is worth assessing persistent changes rather than simply attributing them to age.

When the thyroid is underactive

An underactive thyroid, or hypothyroidism, produces too little thyroid hormone. This usually develops gradually, so the signs can be difficult to recognise. One common cause is Hashimoto’s thyroiditis, an autoimmune condition in which the immune system affects thyroid tissue.

Possible symptoms include:

• Persistent tiredness or reduced stamina
• Feeling cold more easily than before
• Constipation and dry skin
• Gradual weight gain
• Slower thinking or a low mood

These symptoms do not establish a diagnosis. Sleep problems, anaemia, medication effects and other conditions can cause similar changes. In my assessment, I consider the symptoms alongside medical history, examination findings and blood tests.

When treatment is needed, it commonly involves levothyroxine, a replacement thyroid hormone. The dose is individualised and checked with blood tests. In older adults, especially those with heart disease, treatment often starts cautiously. Taking more hormone than needed can affect heart rhythm and bone health.

When the thyroid is overactive

An overactive thyroid, or hyperthyroidism, releases more hormone than the body needs. Possible causes include Graves’ disease, another autoimmune condition, and thyroid nodules that produce hormones independently. Thyroid inflammation can also temporarily release stored hormone.

Typical signs include:

• A fast or irregular heartbeat
• Increased sweating or difficulty tolerating heat
• Trembling hands or inner restlessness
• Weight loss despite an unchanged appetite
• More frequent bowel movements or muscle weakness

In people over 50, the picture is not always obvious. Reduced stamina or an irregular pulse may be more noticeable than restlessness. Persistent palpitations deserve medical assessment, even when there are no other thyroid symptoms. Chest pain, fainting or severe breathlessness require urgent medical attention.

Treatment depends on the cause, hormone levels and overall health. Options may include medicines that reduce hormone production, radioiodine or surgery. Not every option suits every person; the choice requires an individual discussion.

TSH: an important starting point

TSH stands for thyroid-stimulating hormone. It is produced by the pituitary gland in the brain and signals the thyroid to make hormones. For most people, it is the starting point for checking thyroid function.

A high TSH level often suggests that the thyroid is underactive: the pituitary is sending a stronger signal. A low TSH level can suggest an overactive thyroid. However, TSH is not interpreted in isolation. Free thyroxine, called free T4, and sometimes free T3 help clarify the result.

A slightly abnormal TSH does not automatically mean treatment is necessary. If thyroid hormone levels remain normal, the change may be described as “subclinical”. I consider the degree of abnormality, symptoms, age and other health conditions; repeat testing may be appropriate before making a decision.

Medicines, recent illness and supplements can influence results. Please mention everything you take, including biotin supplements marketed for hair and nails, which can interfere with some laboratory tests. Do not stop prescribed medication without advice.

What thyroid ultrasound can—and cannot—show

Ultrasound uses sound waves, not radiation, to show the thyroid’s size and structure. It can identify nodules, fluid-filled cysts and changes in the surrounding tissue. It does not directly measure hormone production, so it complements rather than replaces blood tests.

I may recommend ultrasound when examination reveals an enlarged gland or a lump, or when there are relevant neck symptoms. It is not automatically needed for every abnormal TSH result.

Thyroid nodules are common, particularly with increasing age, and most are benign. Whether a nodule needs monitoring or a needle sample depends on its ultrasound appearance, size and clinical context. Finding a nodule does not automatically mean that treatment is required.

When to arrange an assessment

If tiredness, unexplained weight changes, temperature sensitivity or palpitations persist, arrange a medical appointment. A new neck lump, persistent hoarseness or difficulty swallowing should also be examined. Bringing previous blood results and a medication list can help put the findings into context.

My aim is to distinguish thyroid-related changes from other possible causes and discuss whether testing, observation or treatment is appropriate. Consultations are possible at the three practices in Nürnberg, La Cala de Mijas and Estepona.

This article is general information and does not replace a personal medical consultation.