Thyroid disease- A complete guide on the uncovered facts

What is Thyroid?

This is a large ductless gland in the neck which is responsible to secrete hormones regulating growth and development through the rate of metabolism. The thyroid functions as a large cartilage of the larynx, a projection of which forms the Adam’s apple in humans. The thyroid is a butterfly-shaped gland that is found in the on the front of the neck, below the Adam’s apple, along the front of the windpipe. The thyroid has two side lobes that are connected by a bridge (isthmus) in the middle.

Types of Thyroid- Hyperthyroid and Hypothyroid

There are two different types of thyroid disorders that affects either its structure or function, known as-

Hypothyroidism

Hypothyroidism is a condition due to deficiency of thyroid hormone in the body. In hypothyroidism, the symptoms include- lower heart rate, constipation, intolerance to cold, memory problems, coarse dry hair, slow speech movements, slow walking speed, dry skin, brittle nails, weight gain, fatigue, irritability, infertility, puffy face, loss of eyebrow hair, and heavy menstrual period cycles.

Hyperthyroidism

Hyperthyroidism is due to excessive amounts of thyroid hormone in the body. In hyperthyroidism, the symptoms include- nervousness, anxiety, rapid heartbeat, hand tremor, excessive sweating, sleep problems, sudden weight loss, skin thinning, sweating and tremor.

Foods included for Hyperthyroid and Hypothyroid

The food items included for hyperthyroid include

• Berries
• Broccoli
• Salmon
• Turkey
• Yogurt

The food items included for hypothyroid includes

• Fish
• Nuts
• Fresh fruits and vegetables
• Whole grain
• Beans
• Seaweed
• Dairy products

Foods Excluded for Hyperthyroid and Hypothyroid

The food items that need to be excluded in case of Hyperthyroid include

• Iodine Rich Food
• High-Glycemic Carbs
• Goitrogenic Foods
• Unhealthy Fats
• Caffeine
• Whole Milk
• Enriched Flour
• Added Sugars
• Red Meat
• Avoid Allergic Foods
• Hydrogenated Vegetable Oil
• Dairy Products
• Alcohol

Foods excluded for Hypothyroid includes

• Soy
• Cruciferous vegetables
• Gluten
• Fatty Food
• Sugary Food
• Processed food
• Excess fibre
• Coffee
• Alcohol

Difference between Hypo and Hyper Thyroid

S.NO	Hyperthyroidism	Hypothyroidism
1	Hyperthyroidism refers to increased levels of thyroid hormones.	Hypothyroidism refers to decreased levels of thyroid hormones.
2	Hyperthyroidism can lead to thyrotoxicosis and grave’s disease.	Hypothyroidism doesn’t have such effects on these diseases.
3	There is faster metabolism in hyperthyroidism.	There is a slow metabolism level in case of hypothyroidism.
4	Hyperthyroidism can be treated by anti-thyroid drugs	Hypothyroidism can be treated by supplements of thyroid hormones.
5	Hyperthyroidism shows Higher levels of T3  and lower levels of TSH.	In hypothyroidism, there are lower levels of  T4 and higher levels of TSH.

Both hypothyroidism and hyperthyroidism are extremely different cases.

Blood test to detect Thyroid T3, T4 and TSH and what level is indicated as hyper or hypo?

T3 Testing

The major hormone secreted by the thyroid gland is thyroxine, also called T4 as it contains four Iodine atoms. To exert its effects, T4 is converted to triiodothyronine (T3) by the removal of one Iodine atom. Triiodothyronine occurs mainly in the liver and in certain tissues where T3 acts, such as in the brain. T3 tests are often useful tests for the diagnosis of hyperthyroidism and the associated severity of the hyperthyroidism. Patients who are found to hyperthyroid will have a higher T3 level. In individuals with a low TSH, only the T3 is higher and the FT4 or FTI is normal. T3 testing quite rarely helpful for the hypothyroid patient, since it is the last test to become abnormal. Patients tend to be severely hypothyroid with a higher TSH and low FT4 or FTI, but may have a normal T3. In certain situations such as during pregnancy or while taking birth control pills; higher levels of both T4 and T3 may exist. This is because the Estrogen secretion raises the level of the binding proteins in the body. In such situations, it is better to ask for both the tests TSH and free T4 for correct thyroid evaluation.

T4 Testing

It’s important to understand that TSH evaluation test coming back to normal is not the thumb rule out for the possibility of one’s being hypothyroid or hyperthyroid.If the symptoms still remark towards a hypothyroid diagnosis, the related doctor may measure the level of free T4 (the portion of total T4 thyroid hormone that is available to the tissues) in one’s bloodstream. People who are hypothyroid will actually have higher levels of TSH and lower levels of T4—the doctor may refer this as the “primary hypothyroidism.” This occurs mainly because the pituitary gland recognizes the thyroid as to not producing enough hormones, as required by the body. As a result, the pituitary would release enough TSH as an effort to stimulate the thyroid into producing the relevant hormone. But if the thyroid still isn’t working properly, it will not react to the signals as produced from the pituitary. This in turn leads to higher levels of TSH and lower levels of free T4. If the free T4 levels are too low—the normal range for T4 is 5 to 13.5 micrograms per deciliter—this is an indicator of hypothyroidism, even if the previous TSH tests resulted to be normal. Also, the normal ranges may vary from lab to lab.

TSH Testing

For diagnosing hypothyroidism and hyperthyroidism doctor takes into account both the symptoms and the results of a thyroid stimulating hormone (TSH) test. In essence, hyperthyroidism is believed to be the result of higher levels of thyroxine and low or nonexistent level of TSH and hypothyroidism is the result of increase in TSH Levels.The pituitary gland stimulates the release of these hormones into the bloodstream through TSH, thus it makes sense that the initial line of testing for hyperthyroidism and hypothyroidism is based on the levels of TSH. The doctor measures the TSH levels with the blood test. TSH levels are determined by ranges (all figures in mU/L—milliunits per litre). Mentioned below are the Normal ranges  but this may vary from lab to lab.

Normal Levels for TSH:

• Adults – 0.4–4.2 microunits per milliliter (mcU/mL) or 0.4–4.2 milliunits per litre(mU/L).
• Children – 0.7–6.4 mcU/mL or 0.7–6.4 mU/L.
•  Newborns (1-4 days) – 1–39 mcU/mL or 1–39 mU/L

Hence If the levels of TSH goes lower than the above mentioned levels it is detected as Hyperthyroidism and hence doctor will further advice to do T3 and T4 testing  and when the TSH levels increases or is higher then the above and also T4 levels are lower then it is generally detected as Hypothyroidism. However, these numbers are not the set standards as normal ranges may vary from individual to individual and may even change over the course of a day. Conclusion:  In some instances thyroid disease may appear in a subtle manner and these symptoms are often mistaken for the natural course of ageing especially when they appear in the elderly. It is for this reason that a correct diagnosis is required. Proper diagnosis of thyroid disease enables the clinician to effectively manage the patient and thus perform the right treatment. The importance of the use of correct thyroid function tests are not only required for the diagnosis of the condition but also for the long- term management of the patient.