What Is The Thyroid Gland and What Are Its Responsibilities?

The thyroid gland is situated in the front neck area just below the Adam’s apple. It is a butterfly-shaped gland which forms part of the endocrine system. This gland receives stimulation from the pituitary gland in the base of the brain and also produces and releases hormones to ensure optimal functioning of the gland. The thyroid gland has numerous responsibilities and plays an important role, especially in maintaining the body’s metabolism. The responsibilities of the thyroid are multifaceted and the thyroid hormones that the gland releases can have a widespread effect on the body.

 

What Does The Thyroid Do?

The thyroid gland produces thyroid hormones known as triiodothyronine (T3) and thyroxine (T4). These are the only known biological hormones in the body that contain iodine. T4 is the hormone that the thyroid produces and secretes the most. Under normal circumstances, the thyroid will produce about 70 - 80 micrograms of T4 per day. This hormone does not have a high activity profile and is thus metabolised in the bloodstream to T3 which is a bioactive form of the hormone.

 

Regulation of T3 Levels in the Body

The body releases less amounts of T3 than T4, but it can be due to the risk that high levels of T3 entail which can cause an extremely high heart and respiratory rate, sweats, anxiety and muscle tremors. Under normal circumstances, the body will produce an average of 15-30 micrograms of T3 per day. The thyroid also produced reverse triiodothyronine (rT3) which is seen to be an inactive end-product of the metabolism of T4 to T3 in the bloodstream.

 

Role of Calcitonin in Calcium Regulation and Bone Health

The thyroid also produces small amounts of calcitonin. This hormone helps to regulate the calcium levels in the body. It typically lowers the calcium in the body by decreasing the calcium concentration in the blood and inhibits the absorption of calcium in the intestines while increasing the release thereof in the urine. It also plays an important role in bone health and bone density by stimulating the deposition of calcium in the bones while stimulating osteoblasts, that build bone, and inhibiting osteoclasts, that break down bone.

 

How Can I Maintain My Thyroid Function?

An important dietary intake for optimal functioning of the thyroid includes the consumption of iodine. Iodine plays an important role in the functioning of the thyroid where it absorbs the iodine and makes thyroid hormone. The recommended daily allowance for adults is 150 micrograms per day. It is important to consume a healthy amount of iodine as too little can lead to an underactive thyroid, while too much can cause an overactive thyroid and have severe repercussions. Food sources containing iodine include iodised salt, better known as table salt, shellfish, fish and seaweed.

 

Can My Thyroid Cause Problems?

Yes, it can. There are a few diseases that are known to be caused due to thyroid-related problems. Studies have also shown that the prevalence of thyroid-related problems increases with age.

 

Common Thyroid Problems

The most common problems that occur with a thyroid are an underactive thyroid, an overactive thyroid, or an enlargement of the thyroid. Keep on reading to discover more about these common thyroid problems.

Underactive Thyroid (Hypothyroidism)

An underactive thyroid is when the thyroid does not produce enough T3 and T4, resulting in a lower metabolism. It is usually caused by insufficient intake of iodine, thyroid removal, or thyroid gland inflammation. Symptoms include cold skin, weight gain, lower heart rate, and carpal tunnel syndrome. Fortunately, medication is available to treat the low levels of thyroid hormone.

Overactive Thyroid (Hyperthyroidism)

An overactive thyroid, or hyperthyroidism, is less common but can still occur. It usually happens due to excess iodine consumption, medications, a benign tumour on the pituitary gland, or inflammation of the thyroid. Symptoms include anxiety, increased heart rate, muscle tremors, and higher heat intolerance. Symptomatic treatment with beta-blockers or radioactive iodine therapy may be considered in severe cases.

Enlarged Thyroid (Goitre)

An enlarged thyroid, known as goitre, is a common occurrence usually resulting from insufficient production of thyroid hormones. The thyroid enlarges in an attempt to compensate and produce more hormones. It can also occur due to insufficient dietary iodine intake. Treatment is typically unnecessary if the goitre does not cause problems. However, thyroid medication or increased dietary iodine may be recommended if it causes issues, particularly if it's associated with an underactive thyroid.

 

How To Diagnose Thyroid Problems

Thyroid problems are usually diagnosed by testing a blood sample for the thyroid stimulating hormone (TSH) as well as checking the levels of T3 and T4. Testing TSH levels can give an indication if a patient has an underactive or an overactive thyroid. Additional tests can be requested in cases where the blood tests are inconclusive. These tests may include a scan of the thyroid or a thyroid ultrasound in order to confirm a diagnosis.