What precautions do you have for checking thyroid function and drawing blood?

Thyroid gland is one of the endocrine organs of human body. It mainly secretes thyroid hormone to promote growth and development and regulate metabolism.

The thyroid gland does not work independently. It is controlled by the headquarters of the human brain. The hypothalamus gives instructions to the pituitary gland, which in turn directs the thyroid gland to work. The thyroid gland also feeds back the work to the pituitary gland and hypothalamus so that the headquarters can adjust the work plan in time.

In this regulatory system, problems in any link may lead to abnormal thyroid function (hereinafter referred to as [thyroid function]). Common thyroid dysfunction includes hyperthyroidism, hypothyroidism, elevated thyroid autoantibodies, etc.

1. What are the main indicators of a skill?

Generally, it includes:

    Thyroid Stimulating Hormone (TSH) Total Thyroxine (TT4) Total Triiodothyronine (TT3) Free Thyroxine (FT4) Free Triiodothyronine (FT3)

There are also two thyroid autoantibodies:

    Thyroid peroxidase antibody (TPOAb) thyroglobulin antibody (TGAb)

Different hospital examination items and reference ranges may vary.

2. When do you need to check your skill?

(1) Self-examination found sudden thickening or mass in the neck.

(2) Symptoms related to thyroid diseases, such as fear of heat or cold, sweaty or dry and rough skin, palpitation or chest tightness, easy hunger or anorexia, emaciation or weight gain, impatience or lack of spirit, exophthalmia, irregular menstruation, amenorrhea, infertility, male impotence, hyposexuality, fever with neck pain, etc.

(3) There are no obvious symptoms, but there are high-risk factors for thyroid diseases. For example:

    Age ≥ 60 years old; Family history of thyroid diseases; There are autoimmune diseases such as type 1 diabetes and pernicious anemia. Previous thyroid surgery; Received head and neck radiotherapy; Drugs that may affect thyroid function are being taken, including glucocorticoid, sex hormone, dopamine, bromocriptine, amiodarone, lithium, phenytoin sodium, etc.

(4) Planned pregnancy or confirmed pregnancy (it is better to check the nail function before 8 weeks of pregnancy).

(5) In addition, the American Thyroid Society recommends that thyroid diseases, especially women, should be examined every 5 years from the age of 35.

3. What factors may affect the determination of thyroid function?

Age, blood drawing time (morning or afternoon), seasonal changes, various diseases (such as severe trauma, craniocerebral trauma, malignant tumor, organ failure, Cushing syndrome, acromegaly, etc.), chronic malnutrition, drugs (as mentioned above), coffee, etc. may all affect the results of thyroid test.

4. What are the precautions for blood drawing?

(1) Work and rest regularly before drawing blood, avoid drinking coffee as much as possible, and avoid eating foods with high iodine content (such as laver and kelp).

(2) Try to avoid using drugs that affect nail function within 1 week before drawing blood. If you cannot stop using influential drugs due to the need of your illness, you should tell your doctor in advance for reference.

(3) If you have diagnosed thyroid diseases and are receiving drug treatment, you do not need to stop taking drugs one week in advance. On the day of blood drawing, you should also take drugs normally to objectively reflect the therapeutic effect of drugs and facilitate doctors to adjust the dosage.

(4) Normal diet has no effect on nail function measurement, so it is not necessary to draw blood on an empty stomach on the day. However, it is necessary to avoid excessive eating, especially after eating a large amount of sugar food. Some patients may need to check liver function at the same time when drawing blood to check nail function. At this time, it is necessary to draw blood on an empty stomach, otherwise it will affect liver function results.

(5) Blood should be drawn in a quiet state to avoid strenuous exercise and emotional tension.

5. How often do you check your nail skill?

(1) Hyperthyroidism:

    Oral drug therapy, if the symptoms have not been controlled, recheck the nail function once every 2 weeks, after the condition is stable, it can be appropriately extended to 4 ~ 6 weeks to recheck once. After radioactive iodine therapy or surgical treatment, recheck once every 2 ~ 4 weeks, if normal, it can be changed to recheck once every six months or so.

(2) Hypothyroidism:

    During the period of drug dose adjustment, reexamination shall be conducted once a month. After the drug dose is stable, reexamination shall be conducted every 3 ~ 6 months.

(3) Thyroid cancer:

  • Patients treated with levothyroxine tablets after operation shall be reexamined once a month during the dose adjustment stage, and shall be reexamined regularly according to the situation after the dose is stable.

(4) Hashimoto’s thyroiditis:

    If it is accompanied by hypothyroidism, it shall be examined according to the reexamination frequency of hypothyroidism patients. If there is no hypothyroidism, the thyroid function shall be reviewed once every six months to one year. Once hyperthyroidism or hypothyroidism-related symptoms occur, the thyroid function shall be reviewed immediately.

(5) Pregnant women:

    Hypothyroidism is examined every 4 weeks before 20 weeks of pregnancy. Thyroid cancer was examined every 4-6 weeks after 20 weeks of pregnancy until delivery and 6 weeks after delivery. Thyroid cancer was examined every 2-6 weeks in patients with hyperthyroidism. Thyroid cancer was examined every 4 weeks until 20 weeks of pregnancy. Only TPOAb or TGAb was positive, and other thyroid function indexes were normal. The examination was conducted every 4-6 weeks in the first half of pregnancy and at least once during 26-32 weeks of pregnancy.

(6) If there are special circumstances, the reexamination cannot be carried out rigidly according to the above-mentioned time, but should be carried out at the frequency suggested by the doctor.