- 1 Thyroid Gland
- 2 Thyroid Stimulating hormones (TSH)
- 3 Thyroid Stimulating Hormone Test (TSH Test)
- 4 TSH Test Results
- 5 Normal TSH tests
- 6 Low TSH Levels
- 7 High TSH Levels
- 8 Elevated TSH (Thyroid Hormones) and Pregnancy
- 9 Hypothyroidism and Pregnancy
A human body is composed of glands which are essential to perform the basic functions of the body’s organ. These glands include the hypothalamus, pineal, pituitary, parathyroid, thymus, islets of Langerhans in the pancreas, ovaries, testes, and the adrenals. The thyroid gland is one of the biggest glands in the human body found in front of the neck, below the larynx which consists of 2 lobes on each side of the windpipe. It secretes hormones called triiodothyronine (T3) and thyroxine (T4) who regulate the rate of metabolism and affect the growth and rate of function of many other systems in the body and also produce calcitonin, which plays a role in calcium homeostasis.
Thyroid Stimulating hormones (TSH)
The thyroid stimulating hormones are peptide hormones secreted from the anterior pituitary glands by the control of the hypothalamus. It secretes hormones thyroxine (T4) and triiodothyronin (T3). These hormones control the cellular metabolic activity. Between the 2 hormones, T3 is 5 times more potent and rapid metabolic action. T3 and T4 accelerate metabolic process by increasing the level of enzymes that contribute to oxygen consumption. They also influence the cell replication, brain development and growth. That is why keeping a normal thyroid TSH level is very important for a good health.
Thyroid Stimulating Hormone Test (TSH Test)
TSH test is the single most effective measurement of the serum thyroid stimulating hormone concentration because of its high sensitivity. As of February this year, the official “normal” reference forTSH test results are at 0.5 to 4.5 or 5.0 mlU/L. Blood samples are taken at the vein of the arms or in case of newborn screenings; it is taken at the heel of the baby.
This test may be ordered by the doctor:
- Diagnose a thyroid disorder
- Screen newborns for an underactive thyroid
- Diagnose female infertility problems
- Monitor thyroid replacement therapy
- Evaluate the function of the pituitary gland
TSH Test Results
The thyroid stimulation hormones have 3 test results- high, low and normal. These have various effects in the human body.
Normal TSH tests
Although the result may be “normal tsh” there are still other factors to consider. One of which is that the T3 and T4 are normal but the TSH is high, subclinical hypothyroidism. If the TSH is low but T3 and T4 are high, subclinical hyperthyroidism may occur. Subclinical hyperthyroidism or subclinical hypothyroidism. Subclinical means that there is no discernible adverse effect on cellular metabolic rates and that the levels of active hormones will still be within the laboratory reference ranges.
Low TSH Levels
If there are low thyroid hormones production, meaning the TSH levels are lower than 5.0mlU/L, the patient has the condition called Hyperthyroidism. There are factors as to why this condition may happen such as heredity, too much thyroid medication, and excess dietary intake of foods with iodine (seaweeds and liver). A condition called Grave’s disease or known as toxic diffuse goiter can lead to this illness. Also, more women are affected with this problem than men. This is the second most prevalent endocrine disease next to diabetes mellitus. This condition often affects women more than men.
The body’s metabolism is increase which makes the person affected feel hotter than everyone else around. Losing weight is slow in this type of disease although they tend to eat more than the others. Patients also feel tired at the end of the day and they have trouble sleeping. Palpitations may occur as well as hand trembling and irregular heartbeat happens. Individuals easily becomes irritated or upset so it is important to consider their feelings.
The symptoms may appear gradually and patients don’t often feel these until their condition is severe. Sometimes, patients may suffer shortness of breath, muscle weakness and chest pain.
There are various and readily available treatment for low TSH levels. One option is to take anti-thyroid drug such as methimazole and propylthiouracil. The goal of this therapy is to prevent the thyroid from producing hormones.
Another option is to have a radioactive iodine therapy. This is the most widely recommended treatment.
These acts by giving a radioactive form of iodine which will be absorbed by the thyroid cells are damaged. This can be taken by mouth without the need to be hospitalized. Another option is the surgery which offers permanent cure.
High TSH Levels
High TSH levels can reveal a condition called Hypothyroidism. This is because there is a high production of thyroid hormones in the body. Factors such as iodine deficiency, or a condition called Hashimoto’s disease, or thyroid destruction.
Basically, the symptoms of hypothyroidism are opposite with that of hyperthyroidism and it is often subtle. This includes fatigue, depression, cold intolerance, excessive sleepiness, dry hair, constipation and others. On severe occasions, there may be puffiness around the eyes, slowing of the heart rate and a drop in body temperature.
To treat this condition, it requires a life-long therapy. Desiccated thyroid was available before and this was obtained from animal thyroids however, the desired effect lacks consistency. Then synthetic levothyroxine is available. Although T3 is more potent than T4, majority of the patients preferred this treatment because of the stability of the hormone and requires only a 1 day dosing unlike T3 which requires more than 1 dosing per day. Ideally, this medicine should be taken 30 minutes before eating and other medications such as antacids or iron contents should be avoided since this interferes with the absorption.
Elevated TSH (Thyroid Hormones) and Pregnancy
According to statistics, 1 out of 500 women have hyperthyroidism during pregnancy. If the condition is mild to moderate, then the pregnant woman and the baby or babies will not experience significant problems and pregnancy is expected to progress smoothly.
However with severe or low TSH, infection is likely to occur, iron-deficiency anemia and high blood pressure accompanied with high protein in the urine will happen. In worst case scenarios, further complications may include spontaneous labor or miscarriage, pre-term labor, low-birth weight babies and even stillbirths. The chance of the baby developing hyperthyroidism is also high.
Hypothyroidism and Pregnancy
Usually, hypothyroidism occurs after pregnancy. This is because antibodies are developed that can cause inflammation of the thyroid after delivery. This results to high TSH level and treatment is long lasting and permanent. However, if during pregnancy, the mother develops hypothyroidism, the treatment is straightforward since there is a high risk for miscarriage. That is why during pregnancy, the mothers are usually tested for thyroid function tests.
If the condition is not treated and the delivery is fast approaching, the mother may develop high blood pressure and risk of pre-term labor. The baby may not develop full intellectual potential. Also, infertility can be a problem if hypothyroidism is developed since it can prevent egg production.
Medical-Surgical Nursing 10th edition by Smeltzer and Bare