Hypothyroidism is a common condition, characterized by low functioning thyroid. Lab testing is routinely conducted to diagnose and monitor thyroid conditions. While assessing your health, there are various other important things to test, as they can actually be contributing to your thyroid dysfunction, or your thyroid can affect them.

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Important Labs to Run if you have Hypothyroidism

Lipid Profile

A lipid profile involves looking at cholesterol, LDL, HDL, triglycerides and more. They help in assessing cardiovascular health.

With low functioning thyroid, we see elevations to LDL-C, triglycerides and total cholesterol and a reduction in HDL-C [15].

Prolactin

This pertains to women, particularly those focused on fertility. For those with infertility, it’s important to realize that reduced thyroid function will increase prolactin, which will disturb menstrual cycles and related hormones [16].

C-Reactive Protein (CRP)

C-reactive protein is an inflammatory marker, associated with heart disease and other inflammatory conditions. It’s been discovered that the thyroid hormone T4 is negatively correlated with CRP. This means when T4 is low, CRP rises. This could be one of the several reasons thyroid function relates to cardiovascular disease [17].

Serum Enzymes

Creatine Kinase (CK)

Creatine kinase is an indicator of muscle breakdown. It can be falsely elevated in cases of hypothyroidism. Patients with elevated CK must ensure thyroid function isn’t causing the abnormal CK. [18].

Aspartate Aminotransferase (AST)

Aspartate aminotransferase is an indicator of liver damage. It can be falsely elevated in cases of hypothyroidism. Patients with high AST will undergo further testing to see why AST is high, and thyroid must be considered [18].

Lactate Dehydrogenase (LDH)

Lactate dehydrogenase is an enzyme associated with general tissue damage, and will be elevated in those with blood or liver disease. Low functioning thyroid can elevate LDH [18].

Serum Sodium

Sodium is important for nerve and muscle function. Low functioning thyroid could result in low sodium. It should be noted, this only occurs in long term, untreated hypothyroidism [19].

Urinalysis (Proteinuria)

Proteinuria is caused by excessive proteins loss through the kidneys. When proteins are lost, thyroid hormones will be lost too. This will result in elevated TSH, low T3 and low T4. Anytime a person tests positive for hypothyroidism, it’s important to treat the thyroid, but also look at urinalysis and proteinuria.

Complete Blood Count (Anemia)

Anemia is a condition where you lack enough healthy red blood cells to carry oxygen to your tissues. Thyroid function is closely related because thyroid hormones (T3 and T4) assist in making those red blood cells. Having either high or low thyroid function can result in different types of anemia. Anyone with thyroid disease and any form of anemia, must investigate if one is causing the other [20].

Summary

The thyroid affects many aspects of health. Low or high functioning thyroid can affect other markers in routine lab testing. It’s important to get to the cause of dysfunction, so anyone with thyroid conditions needs to be aware of the above relationships.