Hypothyroidism (underactive thyroid) is a condition where the thyroid gland doesn't produce enough thyroid hormone. This slows metabolism and affects nearly every organ system.
Key Insight
TSH alone may not tell the whole story. Antibodies reveal autoimmune thyroid disease years before TSH becomes abnormal. If you have Hashimoto's, monitor your cholesterol and B12 too.
Core diagnostic markers for hypothyroidism. These are used to diagnose and monitor your condition.
Thyroid-stimulating hormone is the most sensitive marker for thyroid function. High TSH indicates hypothyroidism.
Active thyroid hormone that affects metabolism, heart rate, and body temperature.
The most active thyroid hormone. Some patients have normal T4 but low T3 conversion.
Hypothyroidism affects multiple body systems. Monitor these to catch complications early.
Antibodies indicate autoimmune thyroid disease (Hashimoto's), the most common cause of hypothyroidism
Present in 90% of Hashimoto's patients. Can be elevated years before TSH changes.
Below 35 IU/mL (normal)
Another marker for autoimmune thyroiditis.
Hypothyroidism raises cholesterol levels. Many patients with "high cholesterol" have undiagnosed thyroid issues.
Thyroid hormone affects cholesterol processing. Low thyroid = high LDL.
Often elevated in hypothyroidism. May normalize with treatment.
Can be elevated in hypothyroidism.
Hashimoto's is associated with B12 deficiency and iron deficiency anemia due to autoimmune overlap
Autoimmune gastritis (pernicious anemia) is common in Hashimoto's.
Above 200 pg/mL
Low ferritin is common in hypothyroid patients. Iron is needed for thyroid hormone production.
Above 30 ng/mL
Hypothyroidism can cause anemia due to decreased red blood cell production.
Thyroid disease affects far more than energy levels. It impacts your heart (cholesterol, blood pressure), your blood (anemia risk), your bones, and your metabolism. If you have Hashimoto's, you're at higher risk for other autoimmune conditions.
Understanding how hypothyroidism connects to other conditions helps you see the bigger picture.
When you select Hypothyroidism as your health focus, these categories are prioritized in your dashboard:
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