The thyroid gland is a small, butterfly-shaped gland in the front of the neck. It produces hormones that control how the body uses energy and affect almost every organ. Let's calmly break down what these hormones are, what they are responsible for, and which tests help determine their levels.
Which hormones the thyroid gland produces
The thyroid gland produces thyroid hormones. In blood tests and examinations, thyroxine (T4) and triiodothyronine (T3) are primarily assessed. Thyroid-stimulating hormone (TSH) is looked at separately. These hormones affect breathing, heart rate, weight, digestion, and mood.
How thyroid hormones are formed and what controls them
Iodine is needed for hormone synthesis — with a pronounced dietary deficiency, the gland's function is impaired. Other conditions can also disrupt production: autoimmune damage to the gland, thyroiditis, surgery or radiation therapy in the neck area, treatment for overactive function, and certain medications.
What thyroid hormones are responsible for
Thyroid hormones regulate energy metabolism and the function of virtually all systems. Heart rate, breathing, body weight, digestion, and mood depend on them. Therefore, when their production is disrupted, symptoms can vary and are not always immediately noticeable.
- Energy metabolism and body weight
- Heart function and pulse rate
- Breathing and digestion
- Mood and clarity of thinking
- Menstrual cycle in women
The effect of thyroid hormones on pregnancy
In pregnant women, untreated thyroid hormone deficiency increases the risk of complications: high blood pressure (preeclampsia), birth defects, preterm birth, or miscarriage. If you are pregnant or planning a pregnancy and have a thyroid condition, tell your doctor: additional examinations will be needed.
What happens with an excess and deficiency of hormones
When the gland produces too many hormones, it is called hyperthyroidism; when too few, it is called hypothyroidism. With hormone deficiency, pronounced fatigue, cold intolerance, weight gain, constipation, difficulty concentrating, low mood, dry skin and hair, hoarseness, and irregular or heavy menstruation occur. Symptoms develop gradually. With an excess of hormones, the condition manifests differently, and it is assessed by a doctor.
A change in hormone levels alone is not a reason to call an ambulance; 103/112 — if there are signs of severe hypothyroidism with a risk of myxedema coma, especially in an elderly person.
Which tests show hormone levels and when to see a doctor
To assess thyroid function, the doctor orders a blood test for TSH and T4, and if necessary, for T3 and thyroid antibodies. Additionally, a neck examination, thyroid ultrasound, and in some cases a biopsy may be performed. You should see a doctor if you notice the listed symptoms: their causes vary, but it is reasonable to check the condition of the gland. The doctor will ask about symptoms, family history, and recent pregnancy.
This material is for reference: it helps to understand the topic but does not replace a doctor's consultation — decisions about examination and follow-up are made by a specialist.
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This content is for reference and does not replace a doctor's consultation. Medical disclaimer