From the Research
Severe hypothyroidism can cause carpal tunnel symptoms, as evidenced by the most recent and highest quality study, which found a causal relationship between thyroid dysfunction, including hypothyroidism, and carpal tunnel syndrome 1. Hypothyroidism leads to the accumulation of mucopolysaccharides in the tissues surrounding the median nerve, causing swelling and compression within the carpal tunnel. This compression results in typical carpal tunnel symptoms including numbness, tingling, and pain in the thumb, index, middle, and half of the ring finger, often worse at night. Some key points to consider in the management of carpal tunnel symptoms in hypothyroidism include:
- Treatment primarily involves addressing the underlying hypothyroidism with thyroid hormone replacement therapy, typically levothyroxine, with dose adjustments based on TSH levels every 6-8 weeks 2, 3.
- Many patients experience improvement in their carpal tunnel symptoms once their thyroid function normalizes, though this may take several weeks to months.
- If symptoms persist despite normalized thyroid function, traditional carpal tunnel treatments such as wrist splinting, anti-inflammatory medications, or in severe cases, surgical release may be necessary.
- Increased Body Mass Index (BMI) and presence of clinical symptoms and/or signs of CTS correlated independently with presence of CTS in hypothyroidism, as found in a cross-sectional study 3.
- A meta-analysis found only a modest association between hypothyroidism and CTS, suggesting that confounding and publication bias may still account for part of the remaining excess risk 4. However, the most recent study using Mendelian randomization found a causal relationship between hypothyroidism and carpal tunnel syndrome, supporting the notion that severe hypothyroidism can cause carpal tunnel symptoms 1.