Thyroid Package
- TSH
- Free T3
- Free T4
What Is the Thyroid Package?
The thyroid package consists of blood tests performed to assess the thyroid gland's hormone production and function. The thyroid gland is an important organ located at the front of the neck that produces hormones affecting the body's metabolic rate, energy use, heart rate and body temperature.
An underactive thyroid gland is called hypothyroidism, while an overactive thyroid gland is called hyperthyroidism. Both conditions can cause symptoms such as fatigue, weight changes, palpitations and changes in bowel habits.
The Wellcare Laboratories Thyroid Package includes TSH, Free T3 and Free T4 tests.
Which Tests Are Included in the Thyroid Package?
1. TSH (Thyroid-Stimulating Hormone)
TSH is secreted by the pituitary gland in the brain and regulates the thyroid gland's hormone production. It is generally the first-line and most important blood test for assessing thyroid function.
High TSH: Usually suggests an underactive thyroid gland.
Low TSH: Usually suggests an overactive thyroid gland.
Normal TSH: Indicates normal thyroid function in most people whose pituitary-thyroid system functions normally.
A TSH result should not be assessed in isolation but, when necessary, together with free thyroid hormone levels.
2. Free T4 (sT4 – Free Thyroxine)
Free T4 is the biologically available portion of the main hormone produced by the thyroid gland that is not bound to proteins in the blood.
When assessed together with TSH, it helps identify thyroid hormone deficiency or excess.
Low sT4: May suggest thyroid hormone deficiency.
High sT4: May suggest thyroid hormone excess.
3. Free T3 (sT3 – Free Triiodothyronine)
T3 is a thyroid hormone that affects metabolism. Measuring Free T3 may provide additional information, particularly in some patients with suspected thyroid hormone excess.
Elevated T3 may be detected in some patients with hyperthyroidism who have low TSH and normal free T4 levels.
However, the free T3 test is generally not the first-line test for diagnosing hypothyroidism. In addition, because it has limitations related to the measurement method, results should be interpreted alongside clinical findings.
How Are Thyroid Tests Interpreted?
Reference ranges for thyroid tests may vary depending on the laboratory method used, age and pregnancy status.
The table below shows common patterns of results that may be encountered when thyroid hormone levels are assessed together.
| TSH | Free T4 | Free T3 | Possible interpretation |
|---|---|---|---|
| Normal | Normal | Normal | Thyroid function generally normal |
| High | Low | Normal or low | Overt primary hypothyroidism |
| High | Normal | Usually normal | Subclinical hypothyroidism |
| Low | High | Normal or high | Hyperthyroidism / thyrotoxicosis |
| Low | Normal | High | T3-predominant thyrotoxicosis |
| Low | Normal | Normal | Subclinical hyperthyroidism |
| Low or inappropriately normal | Low | Variable | Possible central hypothyroidism |
Important: This table alone cannot be used to make a definitive diagnosis. Medications, pregnancy, acute illnesses and certain laboratory interferences may alter results. A normal TSH level also does not completely rule out rare thyroid disorders of pituitary origin.
What Is the Normal TSH Range?
Many laboratories may use an approximate TSH range of 0,4–4,0 mIU/L for adults. However, this range is not a universal diagnostic threshold.
Results should be assessed using the laboratory-specific reference ranges stated in the test report.
Interpretation may differ, particularly in pregnant women, children, older adults and people receiving treatment for thyroid disease.
What Happens When the Thyroid Is Underactive? (Hypothyroidism)
Hypothyroidism is a condition in which the thyroid gland cannot produce sufficient amounts of the hormones the body needs.
Common symptoms include:
- Persistent fatigue and weakness
- Feeling cold and intolerance to cold
- Constipation
- Dry skin and hair loss
- A tendency to gain weight
- Difficulty concentrating
- Menstrual irregularities
One common cause of hypothyroidism is Hashimoto's thyroiditis, in which the immune system affects the thyroid gland.
Additional antibody tests, such as Anti-TPO, may be performed on a doctor's recommendation in people with suspected Hashimoto's disease. These tests are not included in the standard Thyroid Package.
What Happens When the Thyroid Is Overactive? (Hyperthyroidism)
Hyperthyroidism is a condition in which the thyroid gland produces more hormones than needed.
Common symptoms include:
- Palpitations and an increased heart rate
- Unintentional weight loss
- Hand tremors
- Excessive sweating and intolerance to heat
- Irritability and restlessness
- Sleep problems
- Increased bowel movements
One cause of hyperthyroidism is Graves' disease. When Graves' disease is suspected, the doctor may request additional tests, such as TSH receptor antibodies (TRAb).
Who Should Have Thyroid Tests?
Thyroid function tests may be particularly useful for people who have symptoms suggestive of thyroid disease or certain risk factors.
These include unexplained fatigue, weight changes, palpitations, feeling cold, hair loss, constipation, menstrual irregularities, a family history of thyroid disease, type 1 diabetes and other autoimmune diseases.
For people who are planning a pregnancy or are pregnant, thyroid assessment should be planned according to individual risk factors and clinical findings.
Not everyone without symptoms or risk factors needs regular comprehensive thyroid hormone panel testing.
Is Fasting Required Before a Thyroid Test?
Fasting is generally not required for TSH, free T3 and free T4 tests.
However:
If you take thyroid hormone medication, discuss the timing of your blood sample collection and medication with your doctor.
Hair, skin and nail supplements containing biotin may affect the results of some thyroid tests. Inform the laboratory about any supplements you take.
Do not stop taking your regular medications without your doctor's advice.
Where Are Thyroid Tests Performed?
The Wellcare Laboratories Thyroid Package is performed using a blood sample collected at our laboratory branches in Nicosia and Kyrenia.
The TSH, free T3 and free T4 tests needed to assess thyroid function can be performed using a single blood sample.
About Thyroid Tests
Frequently Asked Questions
Which hormones are measured in thyroid testing?
TSH is generally used for the initial assessment of thyroid function. Depending on the TSH result and the clinical situation, free T4 and, when necessary, free T3 may be measured. The Wellcare Thyroid Package includes all three tests.
What does high TSH mean?
High TSH usually suggests an underactive thyroid gland. If free T4 is low, this may indicate overt hypothyroidism; if it is normal, subclinical hypothyroidism may be present.
What does low TSH mean?
Low TSH can occur when thyroid hormone levels are elevated. It needs to be assessed alongside free T4 and, when necessary, T3 results.
Can thyroid disease be present even if TSH is normal?
Yes. In rare pituitary disorders or certain specific clinical situations, thyroid hormone levels may be abnormal despite a normal TSH level.
Is fasting required for thyroid testing?
Generally, no. However, fasting may be required if other blood tests are being performed at the same time.
How often should thyroid tests be performed?
Testing frequency is determined by the patient's diagnosis, medications and previous results. There is no single monitoring interval that applies to everyone.
Are Anti-TPO and Anti-Tg tests included in the thyroid package?
No. Our standard package includes TSH, free T3 and free T4 tests. When investigating autoimmune causes of thyroid disease, antibody tests may be performed separately on a doctor's recommendation.
Are thyroid ultrasound and thyroid blood tests the same thing?
No. Blood tests assess the thyroid gland's hormone production, while ultrasound is used to examine the gland's structure, size and nodules. Not every patient needs an ultrasound.