Hyperthyroidism

What hyperthyroidism is

The thyroid produces thyroxine (T4) and triiodothyronine (T3), hormones that regulate the speed of metabolism, heart rate, body temperature and the function of many organs. Production is controlled by the pituitary through thyroid-stimulating hormone (TSH): when thyroid hormones fall, TSH rises, and the reverse. In hyperthyroidism, hormones are raised and TSH is suppressed, that is, low.

Hyperthyroidism (increased production by the gland) should be distinguished from thyrotoxicosis (any state of excess hormone in the blood), which also includes release of stored hormone from an inflamed thyroid or excess intake of hormone from outside. The distinction matters because treatment differs.

What the symptoms are

• Palpitations or tachycardia, sometimes arrhythmia.
• Tremor of the hands, sweating and heat intolerance.
• Unexplained weight loss, often with an increased appetite.
• Anxiety, insomnia, fatigue or muscle weakness.
• More frequent bowel movements and changes in the menstrual cycle.

Symptoms are not specific to the thyroid and are not enough alone for the diagnosis. In older people the condition may be subtle, with fatigue, weight loss or only atrial fibrillation.

What the causes are

The main causes include Graves’ disease, an autoimmune condition in which antibodies stimulate the TSH receptor and drive the thyroid to make too much hormone (it can come with swelling and protrusion of the eyes), and hormone-producing thyroid nodules, single or multiple (see thyroid nodules). Some drugs (for example amiodarone) or large exposures to iodine, including some supplements and contrast agents, can also contribute.

In thyroiditis, stored hormone is released from the inflamed gland. This causes thyrotoxicosis, but not necessarily increased hormone production. The distinction matters for treatment.

How it is diagnosed

Assessment rests on clinical examination and the tests TSH, FT4 and, as appropriate, FT3. A low TSH with high FT4 and/or FT3 confirms thyrotoxicosis. To determine the cause, specific antibodies (anti-TSH receptor), thyroid ultrasound and, when a nodule is present, other tests recommended at a suitable center (for example scintigraphy) may be needed. Ultrasound assesses the structure of the gland; it does not replace measuring hormones. If there are palpitations or an irregular rhythm, cardiology assessment with ECG and, when indicated, Holter ECG is also needed.

How it is treated

Treatment depends on the cause, the severity and the patient’s condition, and includes three main options: antithyroid drugs (which block hormone production, usually for months to a year or two, with a chance of remission in Graves’), radioactive iodine (which gradually destroys the excess thyroid tissue, often leading to hypothyroidism that is then treated with levothyroxine) and surgery (removal of part or all of the gland). Beta-blockers quickly relieve symptoms such as palpitations and tremor, but do not treat the cause. Specialized procedures are recommended at the relevant center.

Do not take iodine supplements and do not change treatment on your own. If fever, severe sore throat or yellowing of the eyes appear during antithyroid treatment, seek medical advice immediately, because these may indicate rare but serious drug effects (severe fall in white blood cells or liver damage). Tell your doctor if you are planning a pregnancy or are pregnant: the choice of drug changes. During treatment, checks are done every 4 to 8 weeks, then every 6 months to a year, or sooner when the doctor considers it reasonable.

Care at Tirana Polyclinic: we offer endocrinology consultation, thyroid ultrasound as indicated and interpretation of tests. When needed, assessment is coordinated with the cardiologist.