Hypothyroidism is a medical condition characterized by low thyroid hormones in the body affecting vital physiological functions. Thyroid hormones, including T3 and T4, are secreted by a small, butterfly-shaped Thyroid Gland located in the front of the neck. Different factors impair the function of the thyroid gland that results in underactive thyroid or insufficient production of the hormone to meet the daily body requirements. [1, 2]
Remember that a low thyroid hormone level or hypothyroidism negatively affects lung function, metabolism, neurological function, body mass index, heart rate, and gastrointestinal health. It is estimated that about 4.6 percent of the US population, or approximately 10 million Americans have hypothyroidism.
The hypothyroidism symptoms vary among individuals. However, it involves the following signs and symptoms. [1, 2, 3]
Hypothyroidism risk factors
Hypothyroidism can occur in any individual, but certain risk factors increase the chances of its development. These risk factors include:
Also, the presence of certain medical conditions increases the risk of hypothyroidism. These conditions include pernicious anemia, Sjogren's syndrome, lupus, diabetes, Turner syndrome, and rheumatoid arthritis. [1, 2, 3]
Causes of Hypothyroidism
Different factors significantly impact the function of the thyroid gland and lead to the development of hypothyroidism. [1, 2, 3] These include:
Hashimoto's Thyroiditis is the most common cause of hypothyroidism. It is an autoimmune disease where the body's immune system attacks the thyroid gland. That results in the development of thyroid inflammation and leads to an impaired thyroid hormone level. Hashimoto's disease is the most common thyroid disorder in America, affecting around 14 million people. It is seven times more prevalent in women than men. Individuals with Hashimoto's disease are also at high risk of other autoimmune diseases. 
Types of Hypothyroidism
Hypothyroidism is divided into three main types based on the etiology of low thyroid hormone in the body. These include:
Moreover, a rare type of hypothyroidism caused by an abnormal expression of the deiodinase three enzyme in tumor tissues is termed Peripheral or Consumptive hypothyroidism. The elevated concentration of the deiodinase three enzyme inactivates thyroid hormone.
Subclinical hypothyroidism is an early hypothyroidism form characterized by an abnormal thyroid-stimulating hormone and a normal thyroxine level with minimal or no symptoms. It occurs in about 15% and 8% of women and men respectively over the age of 60 years. Remember that subclinical hypothyroidism shares the same causes, similar symptoms, and treatment options to other hypothyroidism types. 
It is important to mention that levothyroxine is indicated during pregnancy or in women who want to conceive. It helps prevention of harmful effects of hypothyroidism both on pregnant women and fetal development.
Medical Complications of Hypothyroidism
Untreated hypothyroidism increases the risk of following medical conditions or aggravates their symptoms. 
Sometimes the diagnosis of hypothyroidism is difficult due to the number of symptoms confused with other medical conditions. Medical history, family history, physical examination (enlarged thyroid, dry skin, puffy eyes, etc.), medical symptoms, and different blood tests are performed to diagnose hypothyroidism. The blood tests such as thyroid-stimulating hormone tests and evaluating the level of thyroxin level are highly recommended for hypothyroidism diagnosis. Plus, the physician may order a blood test for Hashimoto's disease to confirm the presence of hypothyroidism. Note that high thyroid-stimulating hormone levels and low levels of thyroxine indicate an underactive thyroid or hypothyroidism. [2, 3]
The hypothyroidism treatment involves the restoration of normal thyroid hormone levels in the body. Moreover, the treatment aims must include complete control over the hypothyroidism symptoms, normalization of thyroid-stimulating and thyroxine hormone level, avoidance of overtreatment, and prevention of medical complications associated with hypothyroidism. It is important to know that hormone replacement such as levothyroxine is the primary therapeutic approach for hypothyroidism management. [4, 8]
Hormone Replacement Therapy
In hormone replacement therapy, synthetic thyroid hormone levothyroxine is prescribed to restore normal thyroid hormone levels in the body. The administration of levothyroxine (T4) maintains an optimal level of thyroxine and thyroid-stimulating hormones that prevent or manage hypothyroidism symptoms. Moreover, it regulates the high cholesterol level, metabolic dysfunctions and also helps the management of weight gain. Primarily, hormone replacement therapy is indicated for a lifetime, but the dose may vary with the patient's condition. Sometimes, Liothyronine (T3) combined with Levothyroxine (T4) is given to the patients when they do not feel better with single hormone therapy. At the beginning of therapy, a levothyroxine dose of 50-75 µg/day is indicated to treat mild to moderate hypothyroidism. However, the initial dose of levothyroxine depends on the patient's weight, age, pregnancy status in women, lean body mass, hypothyroidism type, TSH level, and other medical comorbidities. [4, 8]
Note that all hypothyroid patients respond well to hormone replacement therapy. However, in severe myxedema (life-threatening hypothyroidism), the treatment approaches involve the parenteral administration of levothyroxine (T4), antibiotics, steroids, and optimal oxygen supply. [4, 8]
It is important to know that always consult and take great care about the dosage of synthetic thyroxine as a low dose can't benefit the hypothyroidism symptoms. In comparison, the high doses will result in the development of hyperthyroidism. Thus, it is advised to regularly check the thyroid-stimulating hormone and levothyroxine level for the first 6-8 weeks during hormone replacement therapy; after getting stable, check the levels at an interval of 6 months or can be extended up to 12 months. [4, 8]
The clinical benefits of hormone replacement therapy appear within 3-5 days, but the complete restoration takes 4-6 weeks. Moreover, the normal TSH reference level regulation may take several months due to the modulation of the hypothalamic-pituitary axis. Plus, it is recommended not to switches between different brands or generic formulations of levothyroxine to avoid dose fluctuation. [4, 8]
Different thyroids hormone formulations are available in the market for the management of hypothyroidism. The most popular formulation include Armour Thyroid, Nature Thyroid Tablet, NP Thyroid, Synthroid, and Cytomel. These medications are natural thyroids hormone formulation obtained from animal thyroid glands (usually a pig's) intended for hypothyroidism treatment. Side effects involve temporary hair loss due to the drug-body adjustment. Note that regularly confirm the normal thyroid level to avoid the hyperthyroidism symptoms. [4, 8]
The American thyroid association recommended the evaluation of certain situations or conditions that may alter the thyroxine level. Such as examine the patients for gastrointestinal disorders who need a higher dose of levothyroxine. Plus, always talk with a qualified physician about the initiation or discontinuation of other hormone replacement therapies such as androgen and estrogen hormone during TSH level assessment or levothyroxine therapy. Moreover, other medications such as tyrosine kinase inhibitors, phenobarbital, sertraline, phenytoin, carbamazepine, and rifampin may also alter the Thyroxine level. Also, the concomitant use of proton pump inhibitors, sucralfate, and supplements such as calcium, magnesium, etc., interfere with the levothyroxine absorption. Furthermore, consume the levothyroxine before 35-45 min before breakfast or at least 3 hours post-meal at bedtime for optimal absorption.
Remember that if the hypothyroidism symptoms do not ease with hormone replacement therapy, one must consider and check for other medical causes instead of increasing the levothyroxine dosage. [4, 8]
Hypothyroidism is rarely treated with surgical procedures. Surgery has opted in case of large goiters that negatively impact the function of trachea-esophageal tracts. [4, 8]
Medical studies reported that thyroid replacement therapy exacerbates the co-existing adrenal insufficiency condition. So, remember that treat or evaluate the adrenal insufficiently condition before initiation of thyroid replacement treatment. Moreover, it is important to know that adrenal insufficiency can also occur with subclinical hypothyroidism. Plus, always treat or confirm the adrenal insufficiency during severe hypothyroidism (such as during myxedema coma) for rational treatment options. Furthermore, in heart conditions such as coronary artery disease, ischemic heart disease, etc., medical studies suggested that always start with the lower dose of hormones. Then gradually increase the dosage over time for adjustment with heart conditions. At normal doses, levothyroxine does not cause any severe side effects. But overconsumption of overdosage of levothyroxine hormone increases the risk of poor muscle coordination, fatigue, disturbed sleep pattern, nervousness, excitability, tremors, feeling hotter than normal, osteoporosis, breathing difficulty, muscle weakness, atrial fibrillation, arrhythmias, heart palpitation, and increased appetite. [4, 5]
Natural remedies for hypothyroidism
Different natural interventions are also used to help the hypothyroidism symptoms. These include diet changes and administration of Supplements. Studies reported that selenium levels decrease during Hashimoto's disease and impair thyroxine levels. Selenium Supplementation helps regulate normal T4 levels and improve hypothyroidism symptoms. Moreover, a sugar-free diet also helps prevent aggravation of hypothyroidism symptoms. Studies showed that sugar consumption increases the risk of inflammation that impairs the conversion of T4 to T3 and thus may aggravate or favor the progression of hypothyroidism.
Further, the supplementation of Vitamin B12 improves certain hypothyroidism symptoms, including tiredness and healthy metabolism. Also, the consumption of probiotics restores healthy gut microbiota and improves gastrointestinal symptoms associated with hypothyroidism. Additionally, the supplementation of Zinc, Iron, Iodine, Vit D3 and Tyrosine combined with Iodine help regulate both the stimulating tissue hormone and thyroxine levels. 
Dr. Nicole Sundene, NMD
Dr. Sundene is a Naturopathic Doctor in Scottsdale, Arizona, and is considered a Female Hormone Expert in Women's Health and Bioidentical Hormones. She specializes in Holistic Women's Health for Menopause, Thyroid, Hashimotos, PMS, Perimenopause, Autoimmune, Postpartum, Chronic Fatigue, Depression, Anxiety, Food Allergies, Digestion, Dermatology , Acne, Psoriasis, Eczema and Adrenal Hormonal Conditions. In 1999 she began working for a Hormone Doctor prior to starting Naturopathic Medical School. With over 22 years of experience in both Prescription and Natural women's health and hormones she presents to women the best integrated health solutions for their Chronic Disease. She has been an Herbalist for over 27 years and enjoys teaching women how to use herbs to balance their hormones, nutrition and optimize their health. Dr. Sundene relies on blood testing for her hormone metrics. The hormone testing is covered per the patient's insurance plan and conducted at certain points in the woman's menstrual cycle. To learn more about Hormone Testing for Women Visit: Bioidentical Hormones. Follow Dr. Sundene on Instagram, Twitter and Facebook for more tips on Women's Health, Female Hormones and Naturopathy!