About Lymphocytic Thyroiditis (Hypothyroidism)
Learn about the disease, illness and/or condition Lymphocytic Thyroiditis (Hypothyroidism) including: symptoms, causes, treatments, contraindications and conditions at ClusterMed.info.
Lymphocytic Thyroiditis (Hypothyroidism)
|Lymphocytic Thyroiditis (Hypothyroidism)|
Lymphocytic Thyroiditis (Hypothyroidism) Information
Hypothyroidism definition and facts
How do thyroid hormones work?
The thyroid itself is regulated by another gland that is located in the brain, called the pituitary. In turn, the pituitary is regulated in part by the thyroid (via a "feedback" effect of thyroid hormone on the pituitary gland) and by another gland called the hypothalamus. The hypothalamus releases a hormone called thyrotropin releasing hormone (TRH), which sends a signal to the pituitary to release thyroid stimulating hormone (TSH). In turn, TSH sends a signal to the thyroid to release thyroid hormones. If a disruption occurs at any of these levels, a defect in thyroid hormone production may result in a deficiency of thyroid hormone (hypothyroidism). Hypothalamus - TRH â Pituitary- TSH â Thyroid-T4 and T3 â The rate of thyroid hormone production is controlled by the pituitary gland. If there is an insufficient amount of thyroid hormone circulating in the body to allow for normal functioning, the release of TSH is increased by the pituitary gland in an attempt to stimulate more thyroid hormone production. In contrast, when there is an excessive amount of circulating thyroid hormone, TSH levels fall as the pituitary attempts to decrease the production of thyroid hormone. In persons with hypothyroidism, there is a persistent low level of circulating thyroid hormones.
How is hypothyroidism diagnosed?
A diagnosis of hypothyroidism can be suspected in patients with fatigue, cold intolerance, constipation, and dry, flaky skin. A blood test is needed to confirm the diagnosis.When hypothyroidism is present, the blood levels of thyroid hormones can be measured directly and are usually decreased. However, in early hypothyroidism, the level of thyroid hormones (T3 and T4) may be normal. Therefore, the main tool for the detection of hyperthyroidism is the measurement of the TSH, the thyroid stimulating hormone. As mentioned earlier, TSH is secreted by the pituitary gland. If a decrease of thyroid hormone occurs, the pituitary gland reacts by producing more TSH and the blood TSH level increases in an attempt to encourage thyroid hormone production. This increase in TSH can actually precede the fall in thyroid hormones by months or years (see the section on Subclinical Hypothyroidism below). Thus, the measurement of TSH should be elevated in cases of hypothyroidism. However, there is one exception. If the decrease in thyroid hormone is actually due to a defect of the pituitary or hypothalamus, then the levels of TSH are abnormally low. As noted above, this kind of thyroid disease is known as "secondary" or "tertiary" hypothyroidism. A special test, known as the TRH test, can help distinguish if the disease is caused by a defect in the pituitary or the hypothalamus. This test requires an injection of the TRH hormone and is performed by an endocrinologist (hormone specialist). The blood work mentioned above confirms the diagnosis of hypothyroidism, but does not point to an underlying cause. A combination of the patient's clinical history, antibody screening (as mentioned above), and a thyroid scan can help diagnose the precise underlying thyroid problem more clearly. If a pituitary or hypothalamic cause is suspected, an MRI of the brain and other studies may be warranted. These investigations should be made on a case by case basis.
How is hypothyroidism treated?
With the exception of certain conditions, the treatment of hypothyroidism requires life-long therapy. Before synthetic levothyroxine (T4) was available, desiccated thyroid tablets were used. Desiccated thyroid was obtained from animal thyroid glands, which lacked consistency of potency from batch to batch. Presently, a pure, synthetic T4 is widely available. Therefore, there is no reason to use desiccated thyroid extract. As described above, the most active thyroid hormone is actually T3. So why do physicians choose to treat patients with the T4 form of thyroid? T3 (liothyronine sodium [Cytomel]) is available and there are certain indications for its use. However, for the majority of patients, a form of T4 (levothyroxine sodium [Levoxyl, Synthroid]) is the preferred treatment. This is a more stable form of thyroid hormone and requires once a day dosing, whereas T3 is much shorter-acting and needs to be taken multiple times a day. In the overwhelming majority of patients, synthetic T4 is readily and steadily converted to T3 naturally in the bloodstream, and this conversion is appropriately regulated by the body's tissues.
What are the symptoms of hypothyroidism?
What causes hypothyroidism?
Hypothyroidism is a very common condition. It is estimated that 3% to 5% of the population has some form of hypothyroidism. The condition is more common in women than in men, and its incidence increases with age.Below is a list of some of the common causes of hypothyroidism in adults followed by a discussion of these conditions.
What is hypothyroidism?
Hypothyroidism is a condition characterized by abnormally low thyroid hormone production. There are many disorders that result in hypothyroidism. These disorders may directly or indirectly involve the thyroid gland. Because thyroid hormone affects growth, development, and many cellular processes, inadequate thyroid hormone has widespread consequences for the body.This article will focus specifically on hypothyroidism in adults.
What is subclinical hypothyroidism?
Subclinical hypothyroidism refers to a state in which patients do not exhibit the symptoms of hypothyroidism. These patients also have a normal amount of circulating thyroid hormone. The only abnormality is an increased TSH on their blood work. This implies that the pituitary gland is working extra hard to maintain a normal circulating thyroid hormone level and that the thyroid gland requires extra stimulation by the pituitary to produce adequate hormones. The majority of these patients can be expected to progress to obvious hypothyroidism, especially if the TSH is above a certain level. While there is some controversy, many endocrinologists will treat such patients, especially if they have a high cholesterol blood level. The abnormal cholesterol profile will likely show improvement with thyroid hormone replacement. If the cholesterol levels are normal, and the patient feels well, it is also reasonable to follow these patients without treatment and repeat the blood TSH and thyroid hormone levels in 4 to 6 months to see if more significant hypothyroidism is apparent. Both of these approaches are reasonable and patients should be encouraged to speak with their physicians about specific concerns and preferences.
What's best for you?
If you are concerned that you may have hypothyroidism, you should mention your symptoms to your physician. A simple blood test is the first step in the diagnosis. From there, both you and your doctor can decide what the next steps should be. If treatment is warranted, it is important for you to let your doctor know of any concerns or questions you have about the options available. Remember that thyroid disease is very common and, in good hands, hypothyroidism is easily addressed and treated.
Where is the thyroid located, and what are thyroid hormones?
Thyroid hormones are produced by the thyroid gland. This gland is located in the lower part of the neck, below the Adam's apple. The gland wraps around the windpipe (trachea) and has a shape that is similar to a butterfly - formed by two wings (lobes) and attached by a middle part (isthmus).The thyroid gland uses iodine (mostly available from the diet in foods such as seafood, bread, and salt) to produce thyroid hormones. The two most important thyroid hormones are thyroxine (tetraiodothyronine or T4) and tri-iodothyronine (T3), which account for 99% and 1% of thyroid hormones present in the blood respectively. However, the hormone with the most biological activity is T3. Once released from the thyroid gland into the blood, a large amount of T4 is converted as needed into T3 - the active hormone that affects the metabolism of cells.
A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z
Diseases & Illnesses Definitions Of The Day
- Vancomycin-Resistant Enterococci (VRE) ‐ Are VRE contagious?, How are vancomycin-resistant enterococci (VRE) spread? …
- AAT (Alpha 1 Antitrypsin Deficiency) ‐ Alpha-1 antitrypsin deficiency definition and facts*, Alpha-1 antitrypsin deficiency treatment and management guidelines …
- Achilles Tendon Rupture ‐ Achilles tendon rupture facts, Are there any home remedies for an Achilles tendon rupture? …
- Elemental Mercury Exposure (Mercury Poisoning) ‐ Mercury poisoning definition and facts*, Mercury-Containing Products …
- Jaundice in Adults ‐ Can jaundice in adults be prevented?, Jaundice definition and facts …
- Pregnancy With Breast Cancer (Breast Cancer During Pregnancy) ‐ Can I breastfeed my baby if I have breast cancer?, How is breast cancer diagnosed in pregnant women? …
- Discogram ‐ How do health-care professionals perform a discogram?, How do physicians interpret the results of a discogram? …
- Cancer, Inflammatory Breast (Breast Cancer (Facts, Stages)) ‐
- Shoulder Pain (Shoulder Bursitis) ‐
- Hair Removal ‐ Do any prescription medications or products stop hair growth? …