Understanding the Significance of Total T3, Total T4 & TSH Ultra-Sensitive in Thyroid Profile Testing

The prevalence of thyroid in India is 11.4% in women and 6.2% in men.

The thyroid is a butterfly-shaped gland located in your neck. It produces hormones that control different mechanisms of your body. It produces hormones, primarily Triiodothyronine (T3) and Thyroxine (T4), influencing various bodily functions. 

The normal functioning of the thyroid gland is essential to control our weight, body temperature, muscle strength, and mood. A lack of thyroid hormones in the blood may slow the body function, or if you have too much, many body functions speed up.

Did you know which gland controls the thyroid gland?

The thyroid gland is controlled by a gland located in your brain called the pituitary gland. It makes the hormone TSH, which tells your thyroid how much thyroid hormone your body needs. 

If you are experiencing symptoms like fatigue, restlessness, weight loss or gain, and sensitivity to cold and heat, it signifies you need a thyroid test. A thyroid test helps you to detect the functioning of your thyroid gland. The thyroid profile test allows you to diagnose conditions like hyperthyroidism, hypothyroidism, Graves disease, Hashimoto's disease, and thyroid cancer. 

If you have recently tested for the thyroid test or are planning to take the test, then you must know the significance of T3, T4, and TSH hormones. Read the blog till the end to understand everything about these hormones and more. 

What is Thyroid Profile Total (T3, T4 & TSH) used for?

A Thyroid Profile Total (T3, T4 & TSH) is a blood test used to assess the health of your thyroid gland. It measures the levels of three key hormones:

• It measures the three main hormones: T3 (triiodothyronine), T4 (thyroxine), and TSH. These are produced by your thyroid gland and regulate many bodily functions like metabolism, energy levels, and mood.
• It detects thyroid disorders to identify an underactive (hypothyroidism) or overactive (hyperthyroidism) thyroid gland and Grave's disease, thyroiditis, or Hashimoto's disease.
• Evaluate the symptoms like fatigue, weight changes, and dry skin. Hair loss or mood swings are used to determine thyroid disease.
• The test also monitors the effectiveness of medications used to treat thyroid conditions.
•  To diagnose and monitor the treatment of any suspected thyroid disease, such as hypothyroidism or hyperthyroidism. 
• The thyroid profile test is recommended as a routine health screening to check overall thyroid function.
• To detect an underactive thyroid gland in newborn babies.
• To evaluate and monitor the treatment response of disorders like thyroid nodules and pituitary or hypothalamus gland disorders.

Significance of Total T3, Total T4 & TSH Ultra-Sensitive

Thyroid test measures certain hormones in the blood. The abnormal levels of these three hormones indicate thyroid disease- 

Total T3 (Triiodothyronine)

T3 is an active thyroid hormone that directly impacts metabolism and energy levels. It's the hormone your body uses.

T3 tells how efficiently your body uses energy from food and regulates functions like heart rate and body temperature. However, total T3 levels can be affected by factors like diseases and medications, making them less reliable for initial diagnosis.

Total T4 (Thyroxine)

The inactive form of thyroid hormone is converted to T3 in the body's tissues. Total T4 is often the primary hormone measured in a thyroid profile because its levels are usually stable.

High T4 levels signify the condition of hyperthyroidism. It may cause conditions called thyroiditis or goiter. 

The abnormal results may be due to too much iodine, consumption of high levels of protein trophoblastic disease, or too much thyroid replacement medication.

However, low T4 levels indicate hypothyroidism, dietary issues, iodine deficiency, a pituitary problem, and disease. 

TSH Ultra Sensitive (Thyroid-Stimulating Hormone)

Due to its high sensitivity, it can pick up on minor fluctuations in TSH levels and identify thyroid problems earlier when symptoms might be mild or absent. The pituitary gland produces TSH, which stimulates the thyroid to produce T4. High TSH levels indicate an underactive thyroid (hypothyroidism), while low TSH suggests an overactive thyroid (hyperthyroidism). This helps to monitor the thyroid function in pregnant women. 

This test helps doctors fine-tune the dosage more precisely for those on thyroid replacement medication. Close monitoring of TSH levels can ensure optimal hormone balance and minimize the risk of side effects.

Why are Total T3, Total T4 & TSH Ultra-Sensitive measured together?

These three hormones are measured together to get a comprehensive picture of your thyroid function. 

The reasons why all these three components are measured together are- 

• Interdependency- The pituitary gland produces TSH based on circulating T3 and T4 levels. If T3 and T4 are low, TSH rises to stimulate the thyroid to produce more. Conversely, high T3 and T4 suppress TSH production. 

• Pinpointing the Problem- High T3 and T4 with low TSH indicate an overactive thyroid, while low T3 and T4 with elevated TSH suggest an underactive thyroid. Looking at all three helps pinpoint the location of the problem in the thyroid or pituitary gland.

• Improved Accuracy- The hormone levels can fluctuate slightly for various reasons. Measuring all three doctors can get a more comprehensive view of overall thyroid function and avoid misinterpretations based on a single value.

• Efficiency- Testing all three hormones in one go saves time and resources compared to running separate tests.

Measuring T3, T4, and TSH together provides a more complete, accurate, and efficient way to assess thyroid function and diagnose potential problems.

Why do doctors recommend Thyroid Profile Testing?

Your healthcare provider might recommend thyroid profile testing in the following cases-

• To identify the cause of symptoms such as fatigue, weight changes, anxiety, hair loss, and more. 
• Early detection of diseases.
• To monitor the thyroid disorder 
• Have Family history
• Have Autoimmune Disease
• Have Pregnancy
• Routine Pregnancy

What are the symptoms of abnormal Total T3, Total T4 & TSH levels?

If you observe the following symptoms, do not ignore the signs because these are early indicators that you need a Thyroid test-

Symptoms of Hyperthyroidism 

• Weight loss
• Rapid heartbeat
• Trouble sleeping
• Fatigue
• Shaky hands
• Frequent bowel movements

Symptoms of Hypothyroidism

• Fatigue
• Weight gain
• Sensitivity to cold
• Joint and muscle pain
• Depression
• Constipation
• Irregular Periods

The Bottom Line

Maintaining thyroid health is crucial to support overall health as it impacts metabolism, energy levels, and overall body functioning. If you notice any symptoms of low or high thyroid levels, consult your doctor and get tested. Do not ignore the symptoms because early treatment can help to control your thyroid-related symptoms. Take the thyroid profile test from Redcliffe Labs to learn about your health status and identify the cause of your underlying condition. Early detection and intervention is the key to a healthy and happy life.