What are the Normal Thyroid Stimulating Hormone (TSH) Levels as Per Age?

What are Thyroid Stimulating Hormones (TSH)?

Thyroid Stimulating Hormone or TSH is a hormone that stimulates the thyroid gland to produce essential hormones for your body’s metabolism, such as thyroxine. It is produced by the pituitary gland present in the brain. TSH helps to maintain nerve functions and overall energy levels among other functions.

When the thyroid level in your body is low, a higher level of TSH is produced by the pituitary gland. Similarly, the pituitary gland produces a lower level of TSH if the thyroid level in the body is high. Thus, the TSH level helps in identifying any problem with the functioning of the thyroid.

What are the Normal TSH Levels by Age?

The TSH level in the body is monitored in ranges. The normal TSH level ranges from 0.45 – 4.5 milli-international units per litre (mU/L). However, the normal TSH levels in the body vary as per the age of the person.

Refer to the following table to know the normal body TSH levels as per age:

Age Group	Normal TSH Level Range (mU/L)
0 – 4 days	1.6 – 24.3
2 – 20 weeks	0.58 – 5.57
20 weeks – 18 years	0.55 – 5.31
18 – 30 years	0.5 – 4.1
31 – 50 years	0.5 – 4.1
51 – 70 years	0.5 – 4.5
71 – 90 years	0.4 – 5.2

In men, an abnormality in the TSH level (both high or low) may impact their fertility as it leads to a lesser proper formation of sperms.

Normal TSH Level During Pregnancy

Moreover, the TSH level varies amongst women during pregnancy. Take a look at the normal TSH levels among pregnant women in the table below:

Stage of Pregnancy	Normal TSH Level Range (mU/L)
First Trimester	0.6 – 3.4
Second Trimester	0.37 – 3.6
Third Trimester	0.38 – 4.0

It is essential to keep a check on the TSH level during pregnancy as a higher TSH level poses the risk of miscarriage.

What Does a High TSH Level Mean?

When your TSH level is more than 4.5 mU/L, your thyroid gland is considered underactive. This condition is known as hypothyroidism. Women are more prone to high TSH levels during childbirth, mensuration and menopause.

Take a look at some of the most common symptoms of hypothyroidism or a high TSH level:

Dry skin
Constipation
Weight gain
Weakness
Irregular menstrual cycles or heavy flow
Muscle cramps or joint pain
Slow heart rate
Hair thinning
Brittle nails
Insufficiency to cold
Difficulty in concentrating or focussing

What Does a Low TSH Level Mean?

A low TSH level in your body means that your thyroid gland is hyperactive. This condition is known as hyperthyroidism.

Check out the most common symptoms of hyperthyroidism or a low TSH level:

Increased appetite
Palpitations
Weight loss
Changes in the menstrual cycle
Muscle weakness
Sleep issues
Hair loss or change in hair texture
Vision problems
Feeling shaky or nervous

Summing It Up

The thyroid gland is a vital organ in our body and anything wrong with its functioning can cause your body’s TSH level to drop or spike. However, the normal TSH level is not the same for people of all ages. Hence, refer to the table given above to check the normal TSH level in your body as per your age.