What is the Thyroid-Stimulating Hormone (TSH) Test?

The standard range of TSH is 0.5 to 5.0 mIU/L. High level of TSH implies that the thyroid gland is secreting lower levels of the thyroid hormones and the condition is named hypothyroidism. Reductions in TSH levels indicate that the thyroid gland is producing abnormally high levels of thyroid hormone and the condition is called hyperthyroidism. However, the underlying reasons for the variations in the TSH levels cannot be derived from the TSH test.

You may need a TSH test if you experience the symptoms of an overactive thyroid gland, such as weight loss, anxiety, puffiness, increased heart rate, bulged eyes, sleep disturbances, and hand tremors.

TSH test is also indicated if one experiences the symptoms of an underactive thyroid gland, such as tiredness, weight gain, hair loss, irregularities in menstruation, constipation, and low tolerance to cold temperatures.

TSH is tested using the patient’s blood sample, and the blood sample is collected just like any other blood test using the venipuncture method. The healthcare professional collects blood from the patients' veins in the upper arm into a vial or test tube using a small needle. While the needle goes inside and out of the vein, a slight stinging sensation might be felt. The blood collection will only last for a few minutes.

According to age, the normal level of TSH is as follows:

18-30 years and 31-50 years: 0.5-4.1 mU/L,

51-70 years: 0.5-4.5 mU/L, and

71-90 years: 0.4-5.2 mU/L

Women are more prone to abnormalities in TSH level, and the abnormalities are seen when giving birth, during the menstruation period, and after menopause. The normal TSH level in non-pregnant women ranges from 0.5-5.0 mU/L. In pregnant women, during the first trimester, the TSH level drops.

The healthy TSH level varies between different age groups and genders.

 According to age, the normal level of TSH is as follows:

• 18-30 years and 31-50 years: 0.5-4.1 mU/L,
• 51-70 years: 0.5-4.5 mU/L, and
• 71-90 years: 0.4-5.2 mU/L

The normal TSH level in non-pregnant women ranges from 0.5-5.0 mU/L.

TSH value above five mU/L is generally considered abnormal; however, slight variations across laboratories and in the interpretation of the treating physician are possible.

Stress increases the synthesis of the cortisol hormone from the adrenal gland, which inhibits the release of TSH. So, in patients with either hyperthyroidism or hypothyroidism, stress affects the TSH levels.

Yes, generally, the TSH values above five and especially above 10 are considered abnormally high. The abnormally high TSH levels can result in a condition called myxedema, which has been associated with symptoms such as confusion, irregularities in heartbeat, and hypothermia. Moreover, TSH values above 10 mU/L require long-term thyroid supplements.

No, weight gain is associated with a high level of TSH along with low levels of thyroid hormones like T3 and T4, whereas weight loss occurs when the TSH is low, and T3 and T4 are high.

 Book an appointment or Get a free second opinion from our experts at Yashoda Hospitals today.