Hypothyroidism Definition By Medical
Hypothyroidism definition is a disorder of the thyroid gland that causes the gland can not produce enough hormones. The thyroid gland is a gland located at the front of the throat. The hormones released by the thyroid gland regulate various body metabolic processes including body temperature, body calorie burn rate, and heart rate. If a person suffers from hypothyroidism, the body’s metabolic processes will slow down so that the energy produced by the body will decrease.
Hypothyroidism is divided into two, namely primary and secondary hypothyroidism. Primary hypothyroidism occurs because the thyroid gland does not produce enough thyroid hormones due to thyroid gland abnormalities. Secondary hypothyroidism occurs when the thyroid gland is normal, but does not receive enough thyroid-stimulating hormone (TSH) from the pituitary gland (pituitary).
The thyroid gland uses iodine as the raw material for making hormones. The most important hormones produced by these glands are Triiodothyronine (T3) and thyroxine (T4). T4 hormone levels in the blood is much greater than T3. However, T4 will be converted to T3 which has higher hormone activity.
Often hypothyroidism is asymptomatic at a young age and in its early stages. However, the longer a person develops hypothyroidism, the symptoms will appear slowly. Hypothyroidism can lead to various health problems such as obesity, joint pain, infertility, and heart disease.
Symptoms of Hypothyroidism
The signs and symptoms of hypothyroidism vary in each person, depending on the severity of hypothyroidism suffered. Some common symptoms of hypothyroidism are:
- Dry throat.
- The face is swollen.
- Dry skin.
- Weight gain increases without a clear cause.
- Tired and tired.
- More sensitive to cold weather.
- Memory disorders.
- Heartbeat slows down.
- Pain, stiffness, and swelling of the joints.
- Weak muscles.
- Cholesterol levels in the blood increases.
- Hair loss.
- Tingling and nerve symptoms are pinched.
- Blurred vision.
- Hearing is reduced.
Without proper treatment, symptoms of hypothyroidism will worsen over time. If the thyroid gland is constantly stimulated by hormones from the pituitary gland, the thyroid gland will become swollen (goiter).
Although hypothyroidism often occurs in the elderly, infants and toddlers may also be exposed to hypothyroidism. Some symptoms of hypothyroidism in infants and toddlers are:
Yellowish (jaundice). Yellowish in the baby is caused by bilirubin that can not be broken down by the liver. Bilirubin can accumulate in the human body caused by the destruction of red blood cells.
- Frequent choking.
- Big tongue and prominent.
- The face looks swollen.
- Small muscle size.
- Excessive sleep.
When hypothyroidism in infants and toddlers is not treated properly, infants and toddlers will experience problems in the diet. In addition, without good treatment, even mild hypothyroidism can cause mental development disorders of infants and toddlers.
Symptoms of hypothyroidism in children and adolescents are no different from those of hypothyroidism in adults. However, hypothyroidism in children and adolescents can lead to:
- Slow growth that causes the body to short.
- The late mental development.
- Puberty delay.
- Delayed dental growth remains.
Causes of Hypothyroidism
The causes of hypothyroidism in a person vary greatly, including among others the side effects of therapy, radiotherapy, surgery, and autoimmune diseases. Some of the most common causes of hypothyroidism are:
- Side effects of treatment of hyperthyroidism. Hyperthyroidism is a disease that causes a person to produce excessive thyroid hormone from normal levels. Treatment of hyperthyroidism often uses radioactive iodine and antithyroid drugs. However, sometimes side effects arise from the treatment that actually causes a person is exposed to hypothyroidism.
- Thyroid surgery. Thyroid gland surgery can cause a person to lose some of the thyroid gland. This results in the production of thyroid hormones to be inhibited so that exposed to hypothyroidism, and need to get thyroid hormone for life.
- Drug side effects. Some side effects of drugs can cause hypothyroidism, for example lithium drugs used to treat psychiatric disorders.
- Radiotherapy. Radiotherapy, especially given to the neck region, can interfere with the performance of the thyroid gland and cause hypothyroidism.
- Autoimmune disease. Autoimmune diseases, especially Hashimoto’s thyroid disease, are the most common cause of hypothyroidism. Hashimoto autoimmune disease will cause the immune system to attack the body itself, especially the thyroid gland. This causes the production of thyroid hormone is disrupted so as to trigger hypothyroidism. Can not explain the main cause of the autoimmune disease.
Some of the causes of hypothyroidism that may occur, but rarely appear are:
- Congenital abnormalities. Some babies are born with abnormalities in their thyroid gland or do not even have thyroid gland at all. In some cases, the baby is born with the thyroid gland, but it does not develop well as the baby ages. Infants with congenital thyroid abnormalities often appear normal at the onset of growth.
- Iodine deficiency. Iodine (iodine) is needed to make hormones T3 and T4. Iodine deficiency can trigger hypothyroidism. Conversely, too much consumption of iodine can also trigger hypothyroidism.
- Pituitary gland abnormalities. Lack of hormone TSH produced by the pituitary gland can cause hypothyroidism. Cases of this disorder are often caused by benign tumors in the pituitary gland.
- Pregnancy. Some pregnant women may develop hypothyroidism during or after pregnancy (postpartum hypothyroidism). Postpartum hypothyroidism is caused by pregnant women’s antibodies that actually attack the body itself, including the thyroid gland. If left untreated, hypothyroidism in pregnant women may increase the risk of miscarriage, premature birth, and preeclampsia.
The things that cause a person to have a greater risk for hypothyroidism are:
- Female sex with age above 60 years.
- Has autoimmune disease.
- Pregnant or give birth within the last 6 months.
- Have a family member with a history of thyroid abnormalities.
- Never get treatment using radioactive iodine or antithyroid drugs.
- Never get radiotherapy into the neck or upper chest area.
- Have had thyroid surgery (partial thyroidectomy).
Diagnosis of Hypothyroidism
Several methods can be used and combined to diagnose hypothyroidism. Among others are:
- Blood tests to measure levels of T4 and TSH in the blood. A very low level of T4 in the blood may indicate a condition of hypothyroidism in a person. In some cases, T4 levels in a person’s blood are still in normal numbers, but there is an increase in TSH. The condition is called mild hypothyroidism or subclinical hypothyroidism. Normal TSH is 0.4-4.2 mIU / L. Whereas in patients with subclinical hypothyroidism, the rate of TSH in the blood usually ranges between 4.5-10.0 mIU / L.
- Routine thyroid examination (screening). Thyroid examination is highly recommended for people at risk of hypothyroidism. Thyroid examination in newborns is useful so that hypothyroidism is known from the beginning and prevents baby growth delay. Some people who are also recommended to undergo routine thyroid examination are:-Pregnant women.-Woman over 60 years old.-Patients with type 1 diabetes.-People with autoimmune disease.-Receive radiation to the neck region.
- Thin needle biopsy. A thin needle biopsy to check the thyroid gland can help diagnose hypothyroidism. The target for the implementation of a thyroid biopsy is to determine the presence of nodules in the thyroid that are the clinical signs of hypothyroidism, eutyroidism, and hyperthyroidism. Nodules in the thyroid are often found on examination using CT scan, MRI, and chest X-rays. Biopsy can be assisted using ultrasound.
Treatment of Hypothyroidism
Hypothyroidism is primarily treated using levothyroxine, which is a synthetic T4 hormone, and is given in oral form. The function of levothyroxine is to restore thyroid hormone levels to normal conditions so as to relieve the symptoms of hypothyroidism. Within a week or two of treatment, usually changes in symptoms will feel better. In addition, treatment using levothyroxine will also lower cholesterol levels so that it can lose weight. Treatment using levothyroxine is usually given to the patient for life, but the dose can be adjusted by the doctor while monitoring the hormone levels of TSH on a regular basis.
Some things to consider during treatment using levothyroxine are:
- The dose of levothyroxine should be appropriate. Excessive doses of levothyroxine may cause the patient to experience side effects such as increased appetite, insomnia, rapid heartbeat, and body shakiness.
- Patients with severe coronary heart disease and hypothyroidism should notify the doctor of any health condition at the time of levothyroxine therapy. The doctor will give levothyroxine gradually with a small dose at the beginning of therapy. The dose of levothyroxine will be increased gradually so that the heart can adjust its work by increasing the metabolic rate due to this drug.
- Do not stop to take levothyroxine even though the symptoms of hypothyroidism have subsided and improved. Symptoms of hypothyroidism may reappear if the patient stops taking the drug.
- Absorption of levothyroxine by the body can be affected by several things, especially food consumed. Therefore, doctors should be informed if patients taking levothyroxine also consume the following foods and medicines:- Iron or multivitamin supplements contain iron.-Cholestyramine (a cure for hypercholesterolemia).-Aluminum hydroxide (ulcer medicine).-Supplement calcium.
For pregnant women who have hypothyroidism, it should be noted that the dose of levothyroxine is likely to increase by about 30%. Also during pregnancy and lactation periods, iodine AKG in women will increase from 0.15 mg / day to 0.24-0.29 mg / day. The American Thyroid Association recommends intake of iodine for pregnant and lactating women is 0.25 mg / day in the form of potassium iodide salt (KI). As in patients who are not pregnant hypothyroidism, levotiroksin given to pregnant women should not be consumed along with iron supplements.
Some of the side effects of hypothyroidism treatment using levothyroxine are:
- Can trigger an adrenal gland crisis, especially for people with untreated adrenal gland disorders.
- Can interfere with heart work if levothyroxine treatment is done aggressively, especially in patients who also suffer from heart disease. To avoid this, the dose of levothyroxine should be given in small amounts at the start of a slowly elevated treatment.
- Expected to trigger osteoporosis, especially in patients who have the risk and history of osteoporosis.
- Impaired vision, pseudotumor disorders of the brain, and psychological disorders. However, these side effects are rare.
In patients with subclinical hypothyroidism, it is strongly recommended to increase the intake of iodine through food. This is because the provision of levotiroksin for patients with subclinical hypothyroidism will doubtfully give a good effect, but it can cause harmful side effects.
Complications of Hypothyroidism
If left untreated, hypothyroidism can lead to the following complications:
- Mumps. Continuously stimulated thyroid gland can cause enlargement of the gland (mumps). Although it usually does not provide significant interference, an emerging and enlarged goiter can sometimes inhibit digestion and breathing. Hashimoto’s thyroiditis is the main cause of goiter in a person.
- Miksedema. Miksedema is a complication of long-term hypotyroidism that is undiagnosed and can endanger the life of the patient. The symptoms of myxoedema are, among others, insoluble cold temperatures, severe dizziness, severe fatigue, loss of consciousness, or even coma (myxedema coma). Coma due to myxoedema can be caused by sedatives, infections, and body stress. Miksedema should be treated immediately so that the patient’s life can be saved.
- Abnormalities in infants. Babies conceived and born by women with hypothyroidism will be particularly vulnerable to birth defects. In addition, babies born to women with hypothyroidism may experience delays in physical and mental growth.
- Infertility. Hypothyroidism can interfere with the ovulation process in women that cause infertility.
- Heart disorders. Hypothyroidism can cause heart disease due to the accumulation of bad fats or LDL (low density lipoprotein) in the blood of patients with hypothyroidism. LDL will cause increased cholesterol in the blood and interfere with the heart’s ability to pump blood. This condition can lead to heart enlargement, even heart failure. Cases of mild hypothyroidism may also lead to an increase in blood cholesterol concentration.
- Mental disorders. Hypothyroidism can cause slowing of one’s mental function, one of which is depression. Depression due to hypothyroidism can get worse over time if not treated properly.
- Peripheral nerve disorders. Long-term hypothyroidism can cause peripheral nerve damage that serves to carry nerve impulses from the central nervous to various organs of the body. Damage to the peripheral nerves may be marked by pain, stiffness, and tingling in the hands or feet. In addition, hypothyroidism can also cause the muscles to become weak and uncontrolled.