What is hypothyroidism?
A condition where there is not enough thyroid hormone in the bloodstream is called hypothyroidism. This results in a slower metabolism.
Hypothyroidism is caused by a lack of thyroid hormone in the body. When your metabolism slows down, it has an impact on your entire body. Also known as underactive thyroid disease, hypothyroidism is a medical condition in which the thyroid gland does not produce enough thyroid hormone.
When your thyroid levels are extremely low, this is called myxedema. A very serious condition, myxedema can cause serious symptoms, including:
- A low body temperature.
- Heart failure.
This severe type of hypothyroidism is life-threatening.
In general, hypothyroidism is a very treatable condition. The disease can be managed with medication and regular check-ups with a healthcare provider.
How does my thyroid work?
The thyroid gland is a small, butterfly-shaped organ located in the front of your neck, just under the voice box (larynx). Imagine the middle of a butterfly’s body being positioned in the center of your neck and the wings wrapping around your windpipe area. The primary function of the thyroid is to regulate metabolism. The process of metabolism transforms food into the energy that your body needs to function. The thyroid’s hormones T4 and T3 help to regulate metabolism. These hormones help to regulate the body’s energy usage. They control your body temperature and heart rate.
The thyroid constantly produces hormones which are released and replaced with new ones. This means that your metabolism is working and all of your body’s systems are functioning properly. The pituitary gland, located in the center of the skull below the brain, controls the number of thyroid hormones in the bloodstream. The pituitary gland regulates the levels of thyroid hormone in the body by releasing thyroid stimulating hormone (TSH).
If the amount of thyroid hormones is unbalanced, either too high or too low, it impacts the whole body.
Who is affected by hypothyroidism?
Hypothyroidism can affect people of all ages, genders, and ethnicities. This condition is especially prevalent among women aged 60 or older. After menopause, women are more likely to develop hypothyroidism than at any other time in their lives.
What’s the difference between hypothyroidism and hyperthyroidism?
In hypothyroidism, the thyroid doesn’t make enough thyroid hormone.
The difference between hypothyroidism and hyperthyroidism is quantity. In hypothyroidism, the thyroid makes very little thyroid hormone. The opposite of hypothyroidism is hyperthyroidism, where the thyroid produces too much thyroid hormone. Hyperthyroidism affects the thyroid gland, causing it to produce higher levels of thyroid hormones. This in turn speeds up the metabolism. If you have hypothyroidism, your metabolism slows down.
Many things are the opposite between these two conditions. If you have hypothyroidism, you may find it difficult to cope with the cold. People with hyperthyroidism may not be able to handle hot temperatures. They are opposite extremes of thyroid function. Ideally, you should be in the middle. The treatments for both of these conditions work to get the patient’s thyroid function as close to the average as possible.
Causes and Risk Factors
There are two primary types of hypothyroidism: primary and secondary. This form of hypothyroidism occurs when the thyroid gland doesn’t produce enough thyroid hormone, even though it’s releasing the normal amount of TSH. This lack of thyroid hormones leads to an increase in TSH. Secondary hypothyroidism is less common and usually associated with a central nervous system problem. The focus of this protocol is primary hypothyroidism.
Chronic Autoimmune Thyroiditis (Hashimoto’s Disease)
The most common cause of hypothyroidism in the United States is Hashimoto’s disease, which is chronic autoimmune thyroiditis. The immune system attacks thyroid tissue even though it is supposed to protect the body from harm. Hashimoto’s disease is an autoimmune disorder where the body produces antibodies that attack the thyroid, causing it to become inflamed and impairing its ability to produce hormones. Some patients with Hashimoto’s disease may experience an initial period of hyperthyroidism before their thyroid hormone levels drop. Hashimoto’s Thyrotoxicosis is also known as Hashitoxicosis. This is the name given to the disease when it is in its active state.
Healthcare-Associated Hypothyroidism (Iatrogenic Hypothyroidism)
Medical treatment may cause hypothyroidism either directly or indirectly. A common cause of hypothyroidism is the removal of the thyroid gland due to cancer or persistent autoimmune thyroid disease. Treatment with radioactive iodine can lead to hypothyroidism in a similar way to other thyroid conditions. Radiation treatment to the neck or upper chest region can cause hypothyroidism, whether the radiation was intended originally to treat a thyroid condition or something else.24,25 Some drugs used for non-thyroid conditions may also cause hypothyroidism. Some of the treatments that have been effective in treating bipolar disorder are high doses of lithium carbonate, amiodarone, interferon alpha, and interleukin-2. Other effective treatments include immunotherapies and targeted therapies for cancer.
Environmental and Infectious Causes
Some environmental toxins may disrupt thyroid function and lead to exposure to hypothyroidism. For example, exposure to flame retardants called polybrominated diphenyl ethers (PBDEs) was linked to hypothyroidism in a study of Canadian women.28 A variety of infections, mostly bacterial, can lead to thyroid inflammation and associated thyroid dysfunction.29
Sometimes, diseases that cause systemic problems but are not directly related to the thyroid may lead to thyroid dysfunction. There are a number of systemic diseases that can cause hypothyroidism, such as blood cancers, iron overload, and scleroderma. Non-thyroid diseases that lead to hypothyroidism may be caused by the disease itself or by side effects from treatments. For example, children or adolescents who are treated for leukemia may develop treatment-related hypothyroidism later in life.
Pregnancy puts a lot of stress on a woman’s body, and her thyroid has to work extra hard to make up for it. Women may develop thyroid dysfunction during pregnancy or after giving birth, which usually resolves itself shortly afterward unless the woman has a condition that can cause prolonged thyroid issues.
Iodine Deficiency or Excess
Iodine plays an important role in thyroid physiology. A lack or excess of this trace element can lead to hypothyroidism. In the United States, iodine deficiency is uncommon. If you consume too much iodine, it may be because you are eating too much iodine-rich food, such as seaweed, or because you are taking too many supplements. The Food and Nutrition Board in the United States recommends that adults consume no more than 1,100 micrograms of iodine per day. If you have an underlying thyroid disorder, you may be more likely to have problems with your thyroid due to too much iodine.
Complications and Associated Conditions
The conditions that can develop as a result of hypothyroidism are goiter, depression and other mental disorders, heart problems, infertility and pregnancy complications, and nerve damage. In very few instances, if untreated, hypothyroidism can result in a myxedema coma. This is a dangerous condition brought on by extreme stress, taking sedatives, or an infection. Myxedema coma is a state of intense cold intolerance, and drowsiness, followed by lethargy and unconsciousness.
Fatigue and Weakness
Fatigue, weakness, and decreasing quality of life are all symptoms of low thyroid hormone levels. Many hypothyroid patients experience these symptoms. A decrease in thyroid hormone production and a disruption of the hypothalamic-pituitary-thyroid (HPT) axis can lead to reduced energy production and metabolism, resulting in tiredness.
Thyroid function and gut health are interrelated. In the gut, T4 is converted to T3; however, inflammation may inhibit this process. The microbiome in your intestines plays a key role in how your immune system works. The immune system may produce antibodies and trigger an inflammatory response when potential infectious agents penetrate the intestinal lining. This response may contribute to the development of Hashimoto’s thyroiditis.
Hypothyroidism is a common cause of constipation because it can lead to diminished motility of the intestines. In some cases, this can lead to intestinal obstruction or an enlarged colon.62 This decreased gastric motility is also associated with small intestinal bacterial overgrowth, which may occur in nearly half of people who have hypothyroidism.63 Hypothyroidism is also associated with decreased motility in the esophagus, which can cause difficulty swallowing, heartburn, indigestion, nausea, and vomiting. Other potential gastrointestinal issues that can be caused by thyroid disease include abdominal discomfort, flatulence, and bloating.
Depression and Psychiatric Disorders
If the levels of thyroid hormones change, it can affect brain function. Also, mental disorders have been connected to thyroid dysfunction in the past. Panic disorders, depression, and changes in cognition are frequently associated with thyroid disorders.64-66 In fact, hypothyroidism is often misdiagnosed as depression.67 Also, thyroid hormone replacement has been shown to enhance responsiveness to antidepressant drugs.68
Thyroid hormones are important for brain function and how neurons use energy. Patients with decreased thyroid function may experience a variety of impaired cognitive abilities, including slowed thinking, decreased attentiveness, language difficulties, confusion, difficulty recalling names, and even hallucinations. However, many of these cognitive deficits are reversible with treatment.
Metabolic syndrome is a group of risk factors that affect the heart and increase the chances of developing type 2 diabetes. These risk factors include abdominal obesity, high levels of triglycerides, low levels of high-density lipoprotein (HDL) cholesterol, abnormal blood sugar levels, and high blood pressure. -95 *Hypothyroidism may be caused by metabolic syndrome, which increases the risk of developing hypothyroidism. Hypothyroidism is associated with insulin resistance, and the severity of insulin resistance seems to increase with the severity of hypothyroidism.
Chronic Kidney Disease
CKD is associated with thyroid dysfunction, both overt and subclinical. In a study of over 29,000 people without previous thyroid problems, those with higher TSH levels had lower glomerular filtration rate, which is a measure of kidney function. Individuals with high TSH levels are 31% more likely to develop advanced kidney disease than those with low TSH levels. Treatment of thyroid disease may help to prevent CKD progression in some cases.
How is hypothyroidism diagnosed?
The symptoms of hypothyroidism can be similar to other conditions, making it difficult to diagnose. If any of the following symptoms sound like they could be describing you, it might be worth having a conversation with your doctor about whether or not you could have hypothyroidism. The main way to diagnose hypothyroidism is to measure the level of thyroid-stimulating hormone (TSH) in the blood. Your healthcare provider may also order blood tests for conditions such as Hashimoto’s disease. If the thyroid is enlarged, it may be possible for the provider to feel it during a physical exam during an appointment.
How is hypothyroidism treated?
Most hypothyroidism cases are remedied by supplementing the hormone that the thyroid is not producing. This is typically done with medication. One medication that is commonly used is called levothyroxine. This medication is a pill that you swallow that increases the amount of thyroid hormone your body produces and balances your levels.
Hypothyroidism is a manageable disease. You’ll need to keep taking medication to normalize hormone levels in your body for the rest of your life. If you are careful about managing your illness and keep appointments with your healthcare provider to ensure that your treatment is effective, you can live a normal and healthy life.
What happens if hypothyroidism is not treated?
Hypothyroidism is a medical condition that can become serious and life-threatening if it is not treated by a healthcare provider. If you are not treated, your symptoms can become more severe and can include:
- Developing mental health problems.
- Having trouble breathing.
- Not being able to maintain a normal body temperature.
- Having heart problems.
- Developing a goiter (enlargement of the thyroid gland).
If you have myxedema, you are at risk for developing a myxedema coma, a serious medical condition. This can happen when hypothyroidism isn’t treated.
Can hypothyroidism be prevented?
Hypothyroidism cannot be prevented. The best way to prevent developing a serious form of hypothyroidism or having the symptoms impact your life in a serious way is to watch for signs of the condition. If you have any symptoms of hypothyroidism, you should see your healthcare provider. If you catch hypothyroidism early, it is very manageable to treat.