Why Do I Still Feel Hypothyroid Despite Normal TSH Levels?
Introduction: Living with hypothyroidism can be a challenging journey, especially when your thyroid-stimulating hormone (TSH) levels have been brought back to normal through treatment, yet you still experience symptoms. In this blog post, we'll dissect this perplexing scenario into bite-sized portions to unravel the possible reasons.
Understanding the Hypothalamus-Pituitary Thyroid Axis:
The intricacies of the hypothalamus-pituitary thyroid axis reveal a well-regulated and highly sensitive system. Free T3, the active thyroid hormone, plays a crucial role, in determining the clinical effect and TSH concentration. Any change in intracellular T3 levels can activate or deactivate the hypothalamic-pituitary-adrenal (HPA) system even in the normal range.
Exploring the Possibilities:
1. Beyond Thyroid Issues: Hypothyroidism symptoms might not solely stem from thyroid abnormalities. Ensure no underlying health problems are any other contributing factors to your symptoms. Examples include but are not limited to chronic fatigue syndrome, vitamin or mineral deficiencies, and rheumatological problems. etc
2. Perception after hyperthyroidism: If you've experienced hyperthyroidism in the past, your perception of normal thyroid levels may be skewed for a while. It is possible for what is normal to feel abnormal to you because you were used to higher levels. It may take months for you to adapt.
3. Autoimmune Connections: Autoimmune diseases tend to travel together in packs. It is important to check for other autoimmune conditions, as thyroid diseases often coexist with them.
4. Various problems can be triggered by abnormal thyroid function, including iron deficiency and B12 deficiency. The importance of addressing these issues is paramount to comprehensive health care.
5. Pituitary (central) Pathology: Pituitary issues may manifest at "normal" TSH levels but with clinical hypothyroidism. In this scenario, despite being normal, TSH is inappropriate for the T3 and T4 levels. Consequently, endocrinologists interpret results contextually and look beyond just normal or abnormal values. That is an inappropriate TSH response, even within the acceptable reference range. The concurrent evaluation of T4 and T3 levels can provide valuable information.
6. Outliers in the Population: You might fall into 2% of the population with thyroid levels starting outside the normal laboratory reference range. For instance, you may have a unique setpoint that may be contributing to your problem. If you didn't have thyroid assessments before becoming underactive, you may not be aware of this.
7. Medications and Abnormalities: A small percentage (1.5%) may experience T4 to T3 conversion interference due to medications or other abnormalities. It is important to conduct a comprehensive investigation, which usually requires the expertise of a specialist and is beyond the scope of a generalist. More on this topic in future.
Navigating Treatment with T3:
Although T3 treatment may be necessary for some, it carries potential risks such as cardiotoxicity and bone effects. It may also suppress T4, so it is essential to seek guidance from an endocrinologist, even if T3 levels appear normal, as they can evaluate and test for the consequences of overtreatment.
Conclusion: Hypothyroidism is a complex condition extending beyond measuring TSH, T3 and T4 levels. Delving into the nuances of your health, considering various possibilities, and collaborating with an experienced Endocrinologist can pave the way for a more comprehensive and effective treatment approach.
