What are early warning signs of thyroid problems

by Biocol Labs August 30, 2024

Did you know…

More than 12 percent of the U.S. population will develop a thyroid condition during their lifetime.

An estimated 20 million Americans have some form of thyroid disease.
Up to 60 percent of those with thyroid disease are unaware of their condition.
Women are five to eight times more likely than men to have thyroid problems.
One woman in eight will develop a thyroid disorder during her lifetime.
The causes of thyroid problems are largely unknown.
Undiagnosed thyroid disease may put patients at risk for certain serious conditions, such as cardiovascular diseases, osteoporosis and infertility.
Pregnant women with undiagnosed or inadequately treated hypothyroidism have an increased risk of miscarriage, preterm delivery, and severe developmental problems in their children.
Most thyroid diseases are life-long conditions that can be managed with medical attention.

Introduction

The thyroid is a small, butterfly-shaped gland located in the middle of the lower neck, straddling the trachea. It’s a part of your endocrine system and controls many of your body’s important functions by producing and releasing/secreting certain hormones. The thyroid’s main job is to control the speed of your metabolism (metabolic rate), which is the process of how the body transforms the food we consume into energy. All of the cells in your body need energy to function.

When your thyroid isn’t working properly, it can impact your entire body.

Problems with the thyroid include a variety of disorders that can result in the gland producing too little thyroid hormone (hypothyroidism) or too much (hyperthyroidism).

Thyroid disorders can affect heart rate, mood, energy level, metabolism, bone health, pregnancy and many other functions.

Understanding the Thyroid Gland

The thyroid gland is an endocrine gland that releases hormones directly into the bloodstream. Hormones are chemicals that coordinate different functions in your body by carrying messages through your blood to your organs, skin, muscles and other tissues. These signals tell the body what to do and when to do it.

The thyroid is made of thyroid follicle cells (thyrocytes), which create and store thyroid hormone (mainly T3 and T4), and C-cells, which secrete the hormone calcitonin.

Thyroxine (T4) (inactive form): This is the primary hormone our thyroid makes and releases. Although our thyroid makes the most of this hormone, it doesn’t have much of an effect on your metabolism. Once our thyroid releases T4 into the bloodstream, it can be converted to T3 through a process called deiodination (it occurs mainly in the liver, kidneys, pituitary, CNS, and skeletal muscle).
Triiodothyronine (T3) (active form): Our thyroid produces lesser amounts of T3 than T4, but it has a much greater effect on your metabolism than T4. T3 is mainly produced by conversion of T4 to T3.
Reverse triiodothyronine (RT3): Our thyroid makes very small amounts of RT3, which reverses the effects of T3.
Calcitonin: This hormone helps regulate the amount of calcium in your blood, which helps bone cells process calcium and add it to the bones.

Our body has a complex system for controlling the level of thyroid hormones in your body.

Hypothalamus secretes thyroid-releasing hormone (TRH), which stimulates pituitary gland;
Pituitary gland secretes thyroid-stimulating hormone (TSH). TSH then stimulates your thyroid;
Thyroid releases thyroxine (T4~60% -inactive form) and triiodothyronine (T3~20% - active form) into the bloodstream
Different organs (liver, kidneys, …) converts T4 into its active form T3

In order to make thyroid hormones, your thyroid gland needs iodine, an element found in food (most commonly, iodized table salt, algaes/seaweed, shellfish). Our thyroid gland traps iodine and transforms it into thyroid hormones. If we have too little or too much iodine in your body, it can affect the level of hormones your thyroid makes and releases.

Role of the thyroid in the body

The thyroid gland and its hormones affect almost every organ system of your body, including:

Cardiovascular system: The thyroid helps regulate the amount of blood our heart pumps through our circulatory system (cardiac output), heart rate and strength and vigor of your heart's contraction (contractility of the heart).
Nervous system: When the thyroid isn’t working properly, it can cause symptoms that affect our nervous system, including numbness, tingling, pain or a sense of burning in the affected parts of your body. In addition, hypothyroidism can cause depression and hyperthyroidism can cause anxiety.
Digestive system: The thyroid is involved with how food moves through your digestive system (gastrointestinal motility).
Reproductive system: If our thyroid isn’t working properly, it can cause irregular menstrual periods and issues with fertility.

In summary, thyroid hormones affect the following bodily functions:

Metabolism;
Heart rate;
Breathing;
Digestion;
Body temperature;
Brain development;
Mental activity;
Skin and bone maintenance;
Fertility.

Common Thyroid Disorders

There are several different types of thyroid disease. Some thyroid issues are autoimmune ― they are due to the body’s immune system attacking the thyroid gland. The four main conditions that affect your thyroid include:

Hypothyroidism (underactive thyroid) - is a condition where the thyroid gland does not produce enough thyroid hormone. Hashimoto’s disease it’s an autoimmune condition and it’s the most common cause of hypothyroidism.
Hyperthyroidism (overactive thyroid) - is a condition causing the gland to produce too much thyroid hormone. Graves’ disease is a type of hyperthyroidism; it is an autoimmune disorder that is genetic.
Goiter (enlarged thyroid) - These goiters develop when your thyroid gland doesn’t make enough hormones to meet your body's needs. Your thyroid gland tries to make up for the shortage by growing larger. Could also happen in people who don't get enough iodine in their diet (iodine is necessary to make thyroid hormone).
Thyroid cancer - Thyroid cancer is classified based on the type of cells from which cancer grows.

Overview of Hypothyroidism and Hyperthyroidism

What is Hypothyroidism (underactive thyroid)

One of the most common problems affecting the thyroid gland is hypothyroidism. Happens when your thyroid doesn’t produce and release enough thyroid hormones. This condition is also called underactive thyroid. This causes aspects of your metabolism to slow down. It’s a fairly common condition that affects approximately 10 million people in the United States.

In early stages, hypothyroidism may not cause noticeable symptoms. Over time, hypothyroidism that isn't treated can lead to other health problems, such as high cholesterol and heart problems.

The most common cause of hypothyroidism is **Hashimoto's thyroiditis**, an autoimmune disorder that ultimately causes the gland to stop working.

Can be treated with thyroid hormone replacement therapy (eg. Levothyroxine), replacing the thyroxine (T4) hormone levels.

Hypothyroidism causes:

Hashimoto’s disease, an autoimmune disease.
Thyroiditis (inflammation of the thyroid).
Iodine deficiency.
A nonfunctioning thyroid gland (when the thyroid doesn’t work correctly from birth).
Over-treatment of hyperthyroidism through medication.
Thyroid gland removal.

Hypothyroidism symptoms

The symptoms of hypothyroidism depend on the severity of the condition.

Fatigue/Tiredness
More sensitive to cold
Weight gain
Puffy face
Constipation
Dry skin
Coarse hair and skin
Thinning hair.
Hoarse voice
Muscle weakness, muscle aches, tenderness and stiffness
Menstrual cycles that are heavier than usual or irregular
Slow heart rate (bradycardia)
Depression
Memory problems

What is Hyperthyroidism (overactive thyroid)

Some disorders of the thyroid gland cause it to be overactive and make too many thyroid hormones, a condition called hyperthyroidism. Happens when your thyroid produces and releases more thyroid hormones than your body needs. This condition also is called overactive thyroid. This causes aspects of your metabolism to speed up. Approximately 1 out of 100 people over the age of 12 have hyperthyroidism in the United States.

Hyperthyroidism usually is caused by an autoimmune disease called Graves' disease. It also can be caused by a metabolically active thyroid nodule making too much hormone or by a short-lived thyroid gland inflammation. Graves' disease can be treated with medication, radioactive iodine therapy or surgery.

Hyperthyroidism Causes

Graves’ disease, an autoimmune condition.
Thyroid nodules.
Thyroiditis (inflammation of the thyroid).
Postpartum thyroiditis (inflammation of the thyroid that happens after giving birth).
Excess iodine in your blood from diet and/or medication.
Over-treatment of hypothyroidism through medication.
A benign (noncancerous) tumor in your pituitary gland.

Hyperthyroidism Symptoms

Losing weight without trying
Rapid/fast heart rate (tachycardia)
Irregular heartbeat (arrhythmia) and heart palpitations
Increased hunger
Sweating, increased sensitivity to heat
Changes in menstrual cycles
Changes in bowel patterns, especially more-frequent bowel movements
Diarrhea
Nervousness, anxiety and irritability
Sleep problems, tiredness
Tremor, usually a small trembling in the hands and fingers
Muscle weakness
Thinning skin and brittle hair
Enlarged thyroid gland (goiter)

Early Warning Signs of Thyroid Problems

Slow or rapid heart rate.
Unexplained weight loss or weight gain.
Difficulty tolerating cold or heat.
Cold body extremities
Depression or anxiety.
Irregular menstrual periods.
Thinning hair
Goiter (swelling in the front of your neck, just below the Adam's apple)
A feeling of tightness in your throat area.
A change in your voice, such as hoarseness (scratchy voice).

How the liver and thyroid are connected

The liver modulates the functioning of the endocrine system directly or indirectly in multiple ways. Liver dysfunction is thus predictably associated with various endocrine disorders. The liver produces several important proteins that act as carriers for various hormones and thus indirectly modulate critical endocrine functions (eg. thyroid hormones carriers: thyroid-binding globulin, transthyretin, and albumin).

The liver is a first player in thyroid hormone transport and metabolism (conversion/activation).

Thyroid status is essential for normal organ growth, development and activities, through the precise regulation of cellular activities in every human cell, including hepatocytes (liver cells).

Since thyroid hormones have a role in cell metabolism of the whole body, it is not surprising that the liver may also be affected by hypothyroidism.

A complex interplay exists between the thyroid and the liver in health and disease.

How the thyroid impacts your liver

Thyroid dysfunction (both hypo- and hyperthyroidism) can cause liver function abnormalities, affecting activities of hepatocytes and hepatic metabolism (eg. impaired lipid metabolism → which leads to fatty liver + serum liver enzyme abnormalities).

Thyroid hormones also contribute to bilirubin production and composition, partly because of thyroid involvement in lipid metabolism; furthermore, the Oddi’s sphincter (located in the small intestine) expresses thyroid hormone receptors, and thyroxine (T4) has a direct pro relaxing effect on the sphincter. Which helps move bile from the gallbladder and juices from the pancreas into your small intestine.

How hypothyroidism impacts your liver

Hypothyroidism per se may be associated with slightly increased serum alanine amino-transferase (ALT) and gamma glutamyl transferase (GGT) concentrations, which might be due to diminished lipid metabolism and hepatic steatosis reported in hypothyroidism.

In the general population even subclinical hypothyroidism is associated with an increased risk of developing NAFLD and fibrosis. Several mechanisms might contribute:

Hypothyroidism is associated with dyslipidemia and higher body mass index, which are in turn bound to an increased NAFLD risk;
Hypothyroidism-related insulin resistance may induce lipogenesis, thus promoting storage of free fatty acids in the liver;
Hypothyroidism increases adipocytokines, such as TNFα and leptin, and decreases adiponectin, thereby contributing to hepatic inflammation and fibrosis via a direct effect or indirectly through an increase in oxygen free radicals (oxidative stress).

Another common hepatic disease in which thyroid hypofunction may act as an etiopathogenic factor is gallstone disease. Cholesterol gallstones result from precipitation of cholesterol crystals from supersaturated bile. Hypothyroidism may favor gallstone formation through three different mechanisms:

Decrease in bilirubin excretion rate due to the decreased activity of bilirubin enzyme (UDP-glucuronyltransferase), thereby impairing hepatic bilirubin metabolism;
Hypercholesterolemia, characterized by higher concentrations of both total cholesterol and LDL cholesterol;
Gallbladder hypomotility or impaired contractility, causing delayed emptying of the biliary tract.

How hyperthyroidism impacts your liver

The liver is known to be an important target of thyroid hormone excess due to the relationship between thyroid hormone excess and liver damage.

Serum alkaline phosphatase (ALP) elevation is the most frequent abnormality in hyperthyroidism. Other common biochemical abnormalities involve an increase in AST in 27% of patients, ALT in 37% of patients, GGT in up to 62% of patients, and total bilirubin

How the liver can impact your thyroid

Liver dysfunction (due to excess toxins, environmental pollutants, excess fat accumulation) may therefore be responsible for a large variation in the bioavailability of thyroid hormones.

Conclusion

The liver and thyroid are closely connected in regulating metabolism. The liver helps convert the thyroid hormone thyroxine (T4) into its active form, triiodothyronine (T3). This active hormone controls metabolism throughout the body. A healthy liver is essential for proper thyroid function, while thyroid hormones, in turn, influence liver metabolism and cholesterol levels. Dysfunction in one organ can impact the other, leading to metabolic and health issues.

References

American Thyroid Association: https://www.thyroid.org/media-main/press-room/

Cleveland Clinic: https://my.clevelandclinic.org/health/diseases/8541-thyroid-disease

Mayo Clinic: https://www.mayoclinic.org/diseases-conditions/hypothyroidism/symptoms-causes/syc-20350284

https://www.mayoclinic.org/diseases-conditions/hyperthyroidism/symptoms-causes/syc-20373659

Harvard Health Publishing: https://www.health.harvard.edu/a_to_z/hypothyroidism-a-to-z

Kalra S, Bhattacharya S, Rawal P. Hepatocrinology. Med Sci (Basel). 2021;9(2):39. Published 2021 Jun 1. doi:10.3390/medsci9020039

Piantanida E, Ippolito S, Gallo D, et al. The interplay between thyroid and liver: implications for clinical practice. J Endocrinol Invest. 2020;43(7):885-899. doi:10.1007/s40618-020-01208-6