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Having a Neck Mass? When do you need to request for a Thyroid Test?

Are you noticing an enlarging neck mass but no symptoms of hyper or hypothyroidism? If yes, how will you know the origin of your problem and what specific laboratory tests would help determine if it is caused by thyroid malfunction or not?


Neck mass is one of the most common complaints in the out-patient clinics. Some people may notice an enlarging neck mass that causes compressive symptoms. If you feel like there is something firm, nodular and non-painful mass in your neck, it could be due to a thyroid problem. So how do you know when to visit your doctor to clarify your suspicion?


But first, how important is thyroid gland to your body?

The thyroid gland is located anterior to your trachea or near to the Adam’s apple in males. A normal thyroid gland is 12 to 20 grams in size and soft in consistency. It produces two related hormones the T4 and T3.

These hormones play a critical role in maintaining the balance of your metabolic and thermogenic processes in the body.

And who needs to have a Thyroid Function Test?

One of the common causes of a thyroid problem is iodine deficiency. It is prevalent in mountainous regions and in Central South America, Central Africa, and Northern Asia. Health surveys indicate that iodine intake has been falling in Australia and United States. According to World Health Organization, it is estimated that around 2 billion people worldwide are iodine deficient.

In fact one third of the world population has dietary iodine deficiency.

Aside from iodine deficiency, there are many possible causes of thyroid abnormality. So you need to get a thyroid function test if you have

  • Symptoms of frank hyper or hypothyroidism
  • Suspicious thyroid function abnormality such as menstrual abnormalities, dyslipidemia, weight problems, depression, and atrial fibrillation
  • Goiter
  • Thyroid nodules
  • An existing thyroid condition and undergoing treatment.

What are the appropriate laboratory tests to confirm diagnosis?

There are a number of tests that will help verify whether your problem is thyroid in origin. You may get the following tests to confirm diagnosis:


  • TRH or Thyroid Regulating Hormone Assay
  • TSH or Thyroid Stimulating Hormone Assay
  • Total Serum T4 and T3 Assay
  • Thyroglobulin Test
  • Thyroid ultrasound
  • MRI of the Neck
  • Perchlorate Discharge test
  • 24 hour Radioactive Iodine Uptake
  • FNAB of the Thyroid
  • Thyroid antibodies

TRH Assay

The TRH Assay is the most reliable and sensitive test to detect hyper or hypothyroidism. It helps correlate the levels of peripheral thyroid hormones in the body such as T3 and T4. This test will determine whether you have a primary hypothyroidism or a secondary hypothyroidism.

Together with TSH Assay, this test is used to evaluate the hypothalamic-pituitary-thyroid-axis.

TSH Assay

The TSH Assay is requested to determine whether there is a problem with your hypothalamus or anterior pituitary. Knowing the exact cause of the problem will help your doctor in giving you the appropriate management and treatment.

Total Serum T3 and T4 Assay

The Total serum T3 and T4 assay is requested to determine the metabolic function of the thyroid gland. It is requested if there are no co-morbid conditions. It is not requested for pregnant women because of their condition. Pregnancy causes an abnormal level of T3 and T4.

Thyroglobulin Test

The thyroglobulin test is used to determine the presence of thyroid hormone in the blood. Thyroglobulin is produced by the thyroid gland. It also help detects the presence of thyroid malignancy or metastases.

Thyroid Ultrasound

This imaging study is the most specific and most sensitive in measuring the thyroid gland. It will also determine whether the mass is solid, cystic or a combination of both. The thyroid ultrasonography is limited to the thyroid tissues of the neck.

Magnetic Resonance Imaging

MRI of the neck is used to detect presence of goiter and intrathoracic goiter or an extension of the goiter. This is particularly requested if the goiter has a significant size.

Radioactive Iodine Uptake

The RAUI is requested to detect the iodine stores of the thyroid gland. It helps differentiate Grave’s Disease wherein there is an increase uptake of thyroid gland from hyperthyroidism of thyroiditis where there is a low uptake.

Perchlorate Discharge test

This test is used to determine the organification process of the thyroid, although this test is not usually done clinically.

Thyroid Biopsy

The thyroid biopsy is requested to detect benign or not cancerous thyroid conditions such as thyroiditis, subacute granulomatous thyroiditis and benign thyroid nodule. It is also used if there are indeterminate cellular follicular lesions. Your doctor may also request this test, if he or she has suspicions of malignant conditions such as thyroid cancers.

Thyroid antibodies

The thyroid antibody tests that can be requested are:

Other Laboratory Test to Determine the Effects of Thyroid Hormones

The thyroid gland affects other organs of the body. It has systemic effect that affects your metabolism, cardiac muscle contractility, and many others.

The other laboratory tests that can be used to observe the effects of thyroid hormones on the peripheral tissues are:

If you observe any neck mass, it is best to consult your doctor immediately. It is better to get diagnosed early so you won’t have any regrets in the future. There are many affordable lab tests that you can order online and get your laboratory results faster.