Everything You Need To Know About Thyroid Blood Tests


The thyroid is a gland that produces certain substances. These substances circulate in your body to do specific functions to regulate your daily activities. The gland is responsible for making hormones; if these hormones are imbalanced, it causes thyroid disease. It can ultimately affect the functions of your whole body. 

What are thyroid blood tests? 

A blood test is done by taking some blood from the vein to test the thyroid hormone levels. The thyroid blood test determines whether you have a thyroid disease if the range is either above or below the normal range. The initial tests that your doctor will usually recommend if you have any symptoms are TSH or T4. The normal range for thyroid is 0.40 – 4.50 mIU/mL.

Why are thyroid blood tests necessary?

A thyroid test is essential if certain symptoms show up. The prevailing symptoms may worsen your condition. To diagnose the cause of those symptoms, you will need a thyroid blood test to be done. Thyroid disease can interfere with your day-to-day activities. For example, it becomes difficult to walk or do little chores because of extreme fatigue simply. Once you get done with the thyroid test, either you have the disease or not. If you are diagnosed with thyroid disease, then the symptoms can be managed by consulting the doctor. On the other hand, if your range is normal, then other areas can be investigated. 

What are different types of thyroid diseases?

1. Hypothyroidism: this thyroid disease occurs when the thyroid glands do not produce enough hormones to regulate your bloodstream. As a result, it causes various functions of your body to be dysfunctional. It slows down your metabolism, which ultimately affects your body negatively. 

2. Hyperthyroidism: this thyroid disease occurs when the thyroid glands produce excessive hormone hormones than the normal range. As a result, it fastens your metabolism, which may increase your blood pressure or heartbeat. 

3. Thyroid nodules: these are lumps found in the neck either in groups or alone. These are harmless sometimes; other times, they can cause hyperthyroidism or cancer in extreme cases. An ultrasound or a biopsy will be done to find out if the nodules are harmless or harmful. If they turn out to be dangerous, your doctor may advise you to get the surgery done to remove those nodules. 

What causes thyroid disease?

Various reasons cause an imbalance of hormone production in your thyroid glands. A few of them can cause hypothyroidism, and others may cause hyperthyroidism. 

  1. Hypothyroidism: hypothyroidism is when the thyroid glands produce hormones below the normal range. This can be due to two reasons: primary or secondary. Hashimoto’s disease is an autoimmune disease known as chronic lymphocytic thyroiditis or Hashimoto’s thyroiditis. It is hereditary, which means either a family member had it, and it is passed down to you. Your immune system consequently attacks and then damages your thyroid, preventing the glands from producing enough substance. On the other hand, the secondary cause is not directly related to the thyroid; however, any other disease may interrupt the process of thyroid glands producing enough hormones.

2. Hyperthyroidism: it is when the thyroid glands produce hormones above the normal range. The leading cause of hyperthyroidism is Graves disease, where your glands lose control over the production of hormones. Another cause can be thyroiditis. It is inflammation in your thyroid glands that usually occurs after pregnancy in women. TSH having abnormal secretion and excessive taking of thyroid hormones are other reasons to cause hyperthyroidism. 

3. Thyroid nodules: this often leads to the development of hyperthyroidism. Although the cause of it is unknown, the harm is minimal as well. The enlarged tissues may turn into a cyst. The cyst is usually non-cancerous. However, it may contain cancer cells. If your nodule hurts or increases in size, the check-up becomes vital as it may be cancerous. Other reasons could be thyroid disorder or iodine deficiency. 

What are the different symptoms of thyroid disease?

Hypothyroid symptoms can include:

  1. Feeling cold
  2. Fatigue
  3. Dry skin
  4. Forgetfulness
  5. depression
  6. constipation

Hyperthyroid symptoms may include:

  1. muscle weakness
  2. fatigue
  3. hand tremors
  4. sleeping problems
  5. nervousness
  6. irritability
  7. bowel problems
  8. excessive weight loss
  9. period flow may decrease

A thyroid nodule may not be detected or felt unless it starts to hurt or increase in size. It is sporadic to have such symptoms as only a very few numbers of individuals develop cancerous nodules. However, the cyst can be felt in the throat when the doctor investigates. The cyst may contain blood or fluid. 

To conclude: the symptoms mentioned above may not necessarily happen to you. There are high chances that the symptoms may determine what type of thyroid disease you have. But the doctors cannot diagnose the thyroid type only considering your symptoms. The test is necessary to manage the symptoms. 

What are the treatments of thyroid disease?

There is no one treatment for thyroid disease. However, as there are different types of it and causes of it, hence your doctors will prescribe you accordingly. One thing to note is that the thyroid disease is incurable; however, as hopeless as it sounds, it is manageable, and with a thyroid problem, you can still live your everyday life. 

Before deciding your treatment plan, your doctor will examine your complete condition through different tests and symptoms. Additionally, your age, gender, other health conditions and type of thyroid disease plays a vital role in deciding the treatment plan.

Different drugs are introduced to balance the substance production of your thyroid glands. With your hypothyroidism, the production will increase, whereas, with hyperthyroidism, the production of hormones will decrease. The diet plans are also suggested by the doctors so that your overall health may not be affected. Exercises and herbal remedies will help manage your symptoms in a better way. Additionally, certain surgeries are also effective in thyroid problems. Your doctor can only determine and suggest to you how to manage your thyroid hormone levels. 

What are different types of blood tests that are thyroid-related?

  1. (TSH) thyroid-stimulating hormone blood test: this test usually determines the average TSH level in your blood. It represents how much the gland is producing hormones in your blood. If the test shows that your hormones produced are below the range, then it is hypothyroidism, whereas if the hormone level is above the range, then it is hyperthyroidism. The normal range for thyroid per liter of blood is 0.40-4.50 mIU/mL.
  2. 2. T4: the test determines the T4 ranges that are 5.0 – 12.0 ug/dL for adults. Low T4 shows that the thyroid is hypothyroidism, whereas higher than range shows hyperthyroidism.
  3. 3. FT4: proteins usually interfere with the results of T4; hence it gives the inaccurate measurement of thyroid hormones. To eliminate the chance, FT4 is recommended by the doctors. The normal range for this test is 0.9 – 1.7 ng/dL for adults.
  4. 4. T3: this test usually is to diagnose hyperthyroidism; however, low levels can also indicate hypothyroidism. Normal range for T3 is 100 – 200 ng/dL.
  5. 5. FT3: Like T4, T3 too can show inaccurate results when it gets in contact with the proteins. Hence FT3 is tested to eliminate the chances of inaccuracy. The normal range for FT3 is 2.3 – 4.2 pg/mL

There are multiple other blood tests related to the thyroid that you can get. These blood tests are usually the ones that doctors require for initial testing. However, the in-depth investigation of your case might require other thyroid blood tests, which your doctor will recommend.