The condition when there is low thyroid production in body is called hypo thyroidism. It develops when the thyroid gland fails to produce T4 and T3 as the body needs. The condition is also known as under-active thyroid.
Thyroid hormones help in body’s metabolism. Its underproduction slows down the metabolism that causes damage to various organs and tissues of the body and results in life threatening complications.
Sub clinical hypothyroidism:
Patient has no symptoms of hypothyroidism. It refers to elevated TSH level in blood stream but the level of thyroid hormones in blood is normal, it is because the pituitary gland works hard to maintain normal level of thyroid hormones and thyroid gland needs extra stimulation to produce hormones.
The thyroid gland is located in the front part of neck and covers the trachea. It has two lobes attached to the middle part called isthmus hence its shape resembles a butterfly.
Two most important hormones of thyroid are thyroxine (T4) and triiothyronine (T3). After releasing from the thyroid gland T4 is converted into T3 because T3 is more active hormone that affects the metabolism of cells.
Hypothalamus and pituitary gland in brain plays a major role in stimulating thyroid gland to release hormones. Hypothalamus synthesizes and releases a hormone called thyrotropin releasing hormone (TRH) that sends a signal to pituitary gland to release thyroid stimulating hormone (TSH) in the blood stream which in turn sends signal to the thyroid gland and stimulates the thyroid to releaseT4 and T3.
Iodine is used by thyroid gland to produce hormones. Pituitary gland maintains the level of thyroid hormones in blood. If the level of thyroid hormones increases in blood pituitary gland inhibits the release of TSH, if the level of thyroid hormones decreases pituitary gland releases more TSH. Defect in this process leads to hypothyroidism or hyperthyroidism.
Mortality of Hypothyroidism
Untreated hypothyroidism and its complications can leads to death.
The incidence of disease is higher in females.Risk of having this disease increases with age.
Various diseases results in low production of thyroid hormones. Some of the common causes are as follows:
• Iodine deficiency.
• Hashimoto’s thyroiditis:
It is an autoimmune disease and run in families. The thyroid gland becomes large and its ability to make thyroid hormones decreases.
• Destruction of thyroid gland due to radioactive iodine or surgery.
• Lymphocytic thyroiditis:
When the white blood cell called lymphocyte causes inflammation of the thyroid gland, the condition is called lymphocytic thyroiditis. It is common after pregnancy. Most of the women develop normal thyroid function but in some women hypothyroidism persists.
• Congenitally absent thyroid gland.
• Pituitary or hypothalamic disease.
• Medicines used for hyperthyroidism may reduce the level to such an extent to cause hypothyroidism.
Common symptoms of hypothyroidism are:
• Weight gain.
• Intolerance to cold.
• Dry skin.
• Dry hair.
• Excessive sleepiness.
• Swelling of the legs.
• Cholesterol level increases.
• Muscle cramps.
As the disease advances the symptoms gets worse:
• Low body temperature.
• Puffiness around eyes.
• Heart failure.
• Autoimmune thyroid disease.
• Iodine deficiency.
• Ovarian insufficiency.
• Blood test to check for thyroid hormones T3 and T4.
• In early condition of hypothyroidism level of T3 and T4 comes normal.
• Measurement of TSH confirms the diagnosis. TSH level will be elevated in hypothyroidism to enhance the production of thyroid hormones. If there is any disease in pituitary and hypothalamus then the level of TSH will be abnormally low.
• TRH test helps in distinguishing the disease of pituitary and hypothalamus.
• Thyroid scan, clinical history and antibody screening helps in diagnosing the cause of the thyroid problem.
• MRI of brain may be needed in case if pituitary or hypothalamus disease is suspected.
• Synthetic T4, it converts to T3 naturally in the blood stream. It is the stable form of thyroid hormone and one dose is required in a day as compared to T3 that is prescribed multiple times a day as it is short acting.
• Large doses are required in children.
• Approx. 1.6 mg/kg per day is prescribed. Patient with heart disease 25 mg or less of replacement hormone with gradual increase in dose at 6 weeks intervals is recommended.
• Vitamin B and iron rich diet like fresh vegetables and whole grains.
• Antioxidants e.g. tomatoes, grapes, cherries, oranges, etc.
• Exercise is helpful in such cases.
With medications thyroid level returns to normal.
• Heart diseases.
• Low blood pressure.
• Low blood sugar.
• Decreased breathing.
• Below normal temperature.
• Emaciation is more at neck.
• Mucous membranes are dry.
• Great weakness and weariness.
• Consolation aggravates.
• Feels cold even in warm room.
• Indifferent to loved ones.
• Weak with yellow complexion.
• Forgetful, confused and low spirited.
• Increased perspiration.
• Great sensitiveness to cold.
• Aversion to work or exertion.
• Goes into rage over triffle.
• Craving for large amount of sweets.