- Hypothyroidism Symptoms
- Other Health Problems
- Hypothyroidism Causes
- Hypothyroidism Treatments
- Thyroid Cancer
- Anatomy and Function
- Thyroid Cancer Causes
Hypothyroidism, also called an underactive thyroid, causes low levels of thyroid hormone in your body. The thyroid gland releases thyroid hormone which controls your metabolism. The gland works in conjunction with the pituitary gland to release the proper amount of this hormone.
When the gland releases too little thyroid hormone, it is called hypothyroidism. Hyperthyroidism occurs when it releases too much.
Symptoms of hypothyroidism
The main symptoms of hypothyroidism are:
- Tiredness and weakness
- Feeling cold
- Unexpected weight gain
- High cholesterol
- Changes to your menstrual cycle
- Numbness in your extremities
- Low libido
- Dry skin and hair
- Lower voice
- Feeling "foggy"
The symptoms of an underactive thyroid develop gradually. It may take several months or years before your symptoms become severe enough for you to notice and seek medical attention.
What other health problems does hypothyroidism cause?
In some cases, this condition can cause other health issues. Often, treating your hypothyroidism can resolve these symptoms.
Hypothyroidism can lead to problems getting or maintaining erections. That's because in some cases, hypothyroidism is caused by issues with your pituitary gland, which also results in lower testosterone levels. Once you address your low hormone levels, you may see improvement with your erectile dysfunction.
Lack of ovulation
People who experience untreated hypothyroidism while pregnant may experience complications. This is because a pregnant person's thyroid hormones also get passed to the baby. If the baby doesn't get enough, their brains may not develop properly. This can cause developmental delays once the baby is born.
Pregnant people with untreated hypothyroidism may also be more likely to have miscarriages or go into premature labor.
If your thyroid does not produce enough thyroid hormone, then your pituitary gland may continually send thyroid stimulating hormone (TSH). An overload of TSH can cause your thyroid to grow larger. When this happens, it is called a goiter. Much of the time goiters are not harmful. However, if they are large enough, they can cause difficulty with swallowing or breathing.
Myxedema is typically only found in people who have had undiagnosed hypothyroidism for a long time. It is a severe condition that can lead to a lowered body temperature, mental confusion, and even a coma. To avoid myxedema, get your thyroid hormone levels checked if you suspect you have a thyroid issue.
What causes hypothyroidism?
There are several potential causes of an underactive thyroid.
This genetic condition causes the immune system to attack your thyroid gland. Once the thyroid is damaged, it can no longer make enough thyroid hormone. Another name for this condition is chronic lymphocytic thyroiditis.
If your thyroid is inflamed, it may first release too much thyroid hormone for a few weeks or months. Then, it will release too little because it has been depleted. This condition is also called thyroiditis.
The nutrient iodine is added to many types of salt because it is important for thyroid health. Your body needs iodine to create the thyroid hormone.
Treatments for overactive thyroid
If you've had an overactive thyroid in the past, you may have had radiation therapy to damage the thyroid, or you may have had it removed altogether. If you have had either of these treatments, you will need to take synthetic thyroid hormone to avoid symptoms of hypothyroidism.
Treatments for an underactive thyroid
Luckily hypothyroidism is usually easy to treat. Your doctor will likely prescribe a synthetic version of the thyroid hormone. The most popular medication for this is called levothyroxine. You will need to take this medication for the rest of your life. Once you are medicated, your symptoms and complications may reduce greatly or go away completely.
If you are taking medication for an underactive thyroid, it's important to visit your doctor for all follow-up appointments. The amount of medication you need to take may change throughout your life. So, your doctor will check your hormone levels periodically to make sure your current dosage is correct.
Can you have thyroid cancer with normal blood tests?
Thyroid cancer is the abnormal growth and uninhibited multiplication of cells of the thyroid gland. It gradually deteriorates the function of healthy cells, leading to complications in the body. The thyroid gland is part of the endocrine system, which regulates hormones in the body. The thyroid gland absorbs iodine from the bloodstream to produce thyroid hormones, which control a person’s metabolic rate. A healthy thyroid gland is barely palpable. If a tumor develops in the thyroid, it is felt as a lump in the neck. A tumor can be cancerous or benign. A tumor is considered malignant when it can grow and spread to other parts of the body. There is no single blood test that can accurately diagnose thyroid cancer. The results of thyroid function tests (determining the serum T3 and T4 and thyroid-stimulating hormone level) are usually normal in most patients with thyroid cancer. Normal thyroid blood tests do not rule out thyroid cancer.
Tests to diagnose thyroid cancer
- Tumor markers for thyroid cancers: These are the blood tests that detect certain substances. High levels of these substances are often seen in different types of thyroid cancers. However, these tests are not very sensitive and specific ways to diagnose thyroid cancer. They can be used during the treatment of cancer to see if the treatment is working.
- Table. The blood marker for thyroid cancers
Type of thyroid cancer
Carcinoembryonic antigen (CEA)
Medullary thyroid cancer (MTC)
Medullary thyroid cancer (MTC)
All types of thyroid cancer
- Radioiodine scan: This test can detect thyroid cancer and determine if cancer has spread. The patient is asked to swallow a pill containing a safe amount of radioactive iodine (radioiodine). Over a few hours, the thyroid gland absorbs the iodine. Then, the health care provider uses a special device to measure the amount of radiation in the gland. Areas with less radioactivity need more testing to confirm the presence of cancer.
- Imaging scans: Magnetic resonance imaging (MRI), computed tomography (CT) and positron emission tomography (PET) scans can detect thyroid cancer and cancer spread.
- Biopsy: During a fine-needle aspiration biopsy, the health care provider removes cells from the thyroid to test for cancer cells. A sentinel node biopsy can determine if cancer cells have spread to the lymph nodes. The health care provider may use ultrasound technology to guide these biopsy procedures.
Understanding the anatomy and function of the thyroid gland
The thyroid is a small, butterfly-shaped gland situated at the base of the front of the neck, just below Adam's apple.
Cells of the thyroid gland
Thyroid cancer starts when healthy cells in the thyroid change and grow out of control, forming a mass called a tumor. The thyroid gland contains two types of cells:
- Follicular cells: These cells are responsible for the production of thyroid hormone. Thyroid hormone controls the basic metabolism of the body, i.e., how quickly calories are burned. This can affect weight, slow down or speed up the heartbeat, raise or lower body temperature, influence how quickly food moves through the digestive tract, control the way muscles contract and control how quickly dying cells are replaced.
- C cells: These special cells of the thyroid make calcitonin, which is the hormone that participates in calcium metabolism.
What causes thyroid cancer?
Thyroid cancer is a rare type of cancer that affects the thyroid gland. It can occur in age group, although it is most common after 30 years of age, and its aggressiveness increases in older patients. Women are twice as more likely to develop it than men. The most common cause is the change that happens in the deoxyribonucleic acid (DNA) inside thyroid cells, which makes them grow uncontrollably and produce a lump. Other factors that increase the risk include
- Family history of thyroid cancer or thyroid disorders
- Radiation exposure during childhood, such as radiotherapy
- A bowel condition called familial adenomatous polyposis (FAP)
- Acromegaly, a rare condition where the body produces too much growth hormone
- A syndrome called MEN (multiple endocrine neoplasia), which causes multiple cancers in the body
- Low iodine intake
- Exposure to radioactive fallout from nuclear weapons or a power plant accident
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Cleveland Clinic: "Hypothyroidism," "Thyroiditis."
CLINICAL THYROIDOLOGY FOR THE PUBLIC: "Hypothyroidism and risk for heart disease."
Mayo Clinic: "Hypothyroidism (underactive thyroid)," "Hypothyroidism and infertility: Any connection?" "Thyroid disease: can it affect a person's mood?"
National Institute of Diabetes and Digestive and Kidney Diseases: "Hashimoto's Disease." NHS: "Levothyroxine."
Sharma PK. Thyroid Cancer. Medscape. https://emedicine.medscape.com/article/851968-overview
American Thyroid Association. Thyroid Cancer (Papillary and Follicular). https://www.thyroid.org/thyroid-cancer/
Top Can Low Thyroid Cause Other Health Problems Related Articles
Hashimoto's ThyroiditisHashimoto's thyroiditis or chronic lymphocytic thyroiditis is an autoimmune disorder causing inflammation of the thyroid gland. Hashimoto's thyroiditis is a type of hypothyroidism and is the most common cause of hypothyroidism in the US.
Symptoms of Hashimoto's thyroiditis may include dry skin, fatigue, weight gain, feeling cold, excessive sleepiness, dry skin, dry coarse hair, difficulty swallowing, a lump in the front of the throat, muscle cramps, mood changes, vague aches and pains, problems concentrating, leg swelling, constipation, and depression.
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