Question

A patient complains of fatigue, constipation, cold intolerance, flatulence, hair loss, and dry skin. You suspect that the patient may have a thyroid problem.

1. What other questions could you ask this patient?
2. What laboratory tests is the provider likely to order and what are the normal values for those tests?
3. The patient is prescribed levothyroxine. What teaching points should you share about the medication? before use.

Answer 1

1. in case of patient with thyroid problem there are a variety of problems associated with this.so some are ,Untreated hypothyroidism can lead to a number of health problems:

• Goiter. Constant stimulation of your thyroid to release more hormones may cause the gland to become larger — a condition known as a goiter. ...
• Heart problems. ...
• Mental health issues. ...
• Peripheral neuropathy. ...
• Myxedema. ...
• Infertility. ...
• Birth defects.

so ask patient regarding

• history present\past
• nutritional status
• weight gain or loss
• health habbits
• exercise pattern
• wheather patient is on medication
• difficulties faced by patient

2.

Blood Tests: Hypothyroidism can be detected by different blood tests. TSH Test. A thyroid-stimulating hormone or TSH is a blood test that measures the amount of T4 (thyroxine) that the thyroid is being signaled to make. If you have an abnormally high level of TSH, it could mean you have hypothyroidism.

TESTS

Blood tests to measure these hormones are readily available and widely used, but not all are useful in all situations. Tests to evaluate thyroid function include the following:

TSH TESTS
The best way to initially test thyroid function is to measure the TSH level in a blood sample. Changes in TSH can serve as an “early warning system” – often occurring before the actual level of thyroid hormones in the body becomes too high or too low. A high TSH level indicates that the thyroid gland is not making enough thyroid hormone (primary hypothyroidism). The opposite situation, in which the TSH level is low, usually indicates that the thyroid is producing too much thyroid hormone (hyperthyroidism). Occasionally, a low TSH may result from an abnormality in the pituitary gland, which prevents it from making enough TSH to stimulate the thyroid (secondary hypothyroidism). In most healthy individuals, a normal TSH value means that the thyroid is functioning properly.

T4 TESTS
T4 is the main form of thyroid hormone circulating in the blood. A Total T4 measures the bound and free hormone and can change when binding proteins differ (see above). A Free T4 measures what is not bound and able to enter and affect the body tissues. Tests measuring free T4 – either a free T4 (FT4) or free T4 index (FTI) – more accurately reflect how the thyroid gland is functioning when checked with a TSH.

The finding of an elevated TSH and low FT4 or FTI indicates primary hypothyroidism due to disease in the thyroid gland. A low TSH and low FT4 or FTI indicates hypothyroidism due to a problem involving the pituitary gland. A low TSH with an elevated FT4 or FTI is found in individuals who have hyperthyroidism.

T3 TESTS
T3 tests are often useful to diagnosis hyperthyroidism or to determine the severity of the hyperthyroidism. Patients who are hyperthyroid will have an elevated T3 level. In some individuals with a low TSH, only the T3 is elevated and the FT4 or FTI is normal. T3 testing rarely is helpful in the hypothyroid patient, since it is the last test to become abnormal. Patients can be severely hypothyroid with a high TSH and low FT4 or FTI, but have a normal T3.

FREE T3
Measurement of free T3 is possible, but is often not reliable and therefore not typically helpful.

REVERSE T3
Reverse T3 is a biologically inactive protein that is structurally very similar to T3, but the iodine atoms are placed in different locations, which makes it inactive. Some reverse T3 is produced normally in the body, but is then rapidly degraded. In healthy, non-hospitalized people, measurement of reverse T3 does not help determine whether hypothyroidism exists or not, and is not clinically useful.

THYROID ANTIBODY TESTS

The immune system of the body normally protects us from foreign invaders such as bacteria and viruses by destroying these invaders with substances called antibodies produced by blood cells known as lymphocytes. In many patients with hypothyroidism or hyperthyroidism, lymphocytes react against the thyroid and make antibodies against thyroid cell proteins. Two common antibodies are thyroid peroxidase antibody and thyroglobulin antibody. Measuring levels of thyroid antibodies may help diagnose the cause of the thyroid problem. For example, positive anti-thyroid peroxidase and/or anti-thyroglobulin antibodies in a patient with hypothyroidism result in a diagnosis of Hashimoto’s thyroiditis. While detecting antibodies is helpful in the initial diagnosis of hypothyroidism due to autoimmune thyroiditis, following their levels over time is not helpful in detecting the development of hypothyroidism or response to therapy. TSH and FT4 are what tell us about the actual thyroid function or levels.

A different antibody that may be positive in a patient with hyperthyroidism is the stimulatory TSH receptor antibody . This antibody causes the thyroid to be overactive in Graves’ Disease. If you have Graves’ disease, your doctor might also order a thyrotropin receptor antibody test, which detects both stimulating and blocking antibodies. Following antibody levels in Graves’ patients may help to assess response to treatment of hyperthyroidism, to determine when it is appropriate to discontinue antithyroid medication, and to assess the risk of passing antibodies to the fetus during pregnancy.

THYROGLOBULIN
Thyroglobulin is a protein produced by normal thyroid cells and thyroid cancer cells. It is not a measure of thyroid function and it does not diagnose thyroid cancer when the thyroid gland is still present. It is used most often in patients who have had surgery for thyroid cancer in order to monitor them after treatment. Tg is included in this brochure of thyroid function tests to communicate that, although measured frequently in certain scenarios and individuals, Tg is not a primary measure of thyroid hormone function.

NON-BLOOD TESTS

RADIOACTIVE IODINE UPTAKE
Because T4 contains iodine, the thyroid gland must pull a large amount of iodine from the bloodstream in order to make an appropriate amount of T4. The thyroid has developed a very active mechanism for doing this. Therefore, this activity can be measured by having an individual swallow a small amount of iodine, which is radioactive. The radioactivity allows the doctor to track where the iodine goes. By measuring the amount of radioactivity that is taken up by the thyroid gland , doctors may determine whether the gland is functioning normally. A very high RAIU is seen in individuals whose thyroid gland is overactive , while a low RAIU is seen when the thyroid gland is underactive . In addition to the radioactive iodine uptake, a thyroid scan may be obtained, which shows a picture of the thyroid gland and reveals what parts of the thyroid have taken up the iodine.

Test	Abbreviation	Typical Ranges
Serum thyroxine	T4	4.6-12 ug/dl
Free thyroxine fraction	FT4F	0.03-0.005%
Free Thyroxine	FT4	0.7-1.9 ng/dl
Thyroid hormone binding ratio	THBR	0.9-1.1
Free Thyroxine index	FT4I	4-11
Serum Triiodothyronine	T3	80-180 ng/dl
Free Triiodothyronine l	FT3	230-619 pg/d
Free T3 Index	FT3I	80-180
Radioactive iodine uptake	RAIU	10-30%
Serum thyrotropin	TSH	0.5-6 uU/ml
Thyroxine-binding globulin	TBG	12-20 ug/dl T4 +1.8 ugm
TRH stimulation test Peak	TSH	9-30 uIU/ml at 20-30 min
Serum thyroglobulin l	Tg	0-30 ng/m
Thyroid microsomal antibody titer	TMAb	Varies with method
Thyroglobulin antibody titer	TgAb	Varies with method

3. Typically, patients are advised to take their levothyroxine first thing in the morning, at least 30 minutes but preferably an hour before eating, on an empty stomach and with only water. The goal is to achieve consistency in taking the medication to avoid fluctuations in thyroid levels and variable control of symptoms.Levothyroxine is a medicine used to treat an underactive thyroid gland (hypothyroidism). The thyroid gland makes thyroid hormone which helps to control energy levels and growth.

Levothyroxine oral works best if you take it on an empty stomach, 30 to 60 minutes before breakfast. Follow your doctor's dosing instructions and try to take the medicine at the same time each day. Swallow the tablet or capsule whole, with a full glass (8 ounces) of water.

Levothyroxine comes as a tablet and a capsule to take by mouth. It usually is taken once a day on an empty stomach, 30 minutes to 1 hour before breakfast. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take levothyroxine exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Swallow capsules whole; do not chew or crush them. Do not remove the capsule from the package until you are ready to take it.Take the tablets with a full glass of water as they may get stuck in your throat or cause choking or gagging.

If you are giving levothyroxine to an infant, child, or adult who cannot swallow the tablet, crush and mix it in 1 to 2 teaspoons (5 to 10 mL) of water. Only mix the crushed tablets with water; do not mix it with food or soybean infant formula. Give this mixture by spoon or dropper right away. Do not store it for later use.probably start you on a low dose of levothyroxine and gradually increase your dose.

Levothyroxine controls hypothyroidism but does not cure it. It may take several weeks before you notice a change in your symptoms. Continue to take levothyroxine even if you feel well. Do not stop taking levothyroxine without talking to your doctor.