Thyroid problems can cause nausea. While nausea can stem from many causes, when related to thyroid dysfunction, it often appears with other symptoms. These signs can help identify thyroid involvement.
The Thyroid Gland’s Role
The thyroid gland is a small, butterfly-shaped organ located in the front of your neck. It is part of the endocrine system, which produces and releases hormones throughout the body. Its primary function is to produce hormones, mainly thyroxine (T4) and triiodothyronine (T3), that regulate metabolism. Metabolism is the process by which your body converts food into energy, affecting nearly every cell and system.
When the thyroid gland does not function correctly, it can lead to two main conditions: hypothyroidism and hyperthyroidism. Hypothyroidism occurs when the gland produces too few hormones, slowing bodily functions. Hyperthyroidism is an overproduction of hormones, speeding up bodily processes. Both conditions can significantly impact overall health and well-being.
Hypothyroidism and Nausea
Hypothyroidism can cause nausea by slowing various bodily functions, including digestion. Thyroid hormones regulate how quickly food moves through the digestive tract. When these hormone levels are low, gastric emptying can be delayed, meaning food stays in the stomach for longer periods. This prolonged presence can lead to fullness, discomfort, and nausea.
Reduced digestive motility due to low thyroid hormone levels can also contribute to other issues. It can lead to constipation, a common symptom of hypothyroidism. Additionally, slowed gut motility can promote an overgrowth of bacteria in the small intestine, a condition known as Small Intestinal Bacterial Overgrowth (SIBO). SIBO can cause bloating, abdominal pain, and nausea, linking an underactive thyroid to digestive discomfort.
Hyperthyroidism and Nausea
Hyperthyroidism can also cause nausea, though through different mechanisms than hypothyroidism. Excess thyroid hormones speed up metabolism, increasing gut motility. This acceleration can lead to frequent bowel movements or diarrhea, as food passes too quickly for proper nutrient absorption. Rapid transit and digestive upset can contribute to nausea.
Beyond accelerated gut motility, hyperthyroidism can trigger other conditions that induce nausea. Increased anxiety and nervousness are common symptoms of an overactive thyroid, and these can sometimes be accompanied by gastrointestinal distress. Acid reflux is another potential consequence of thyroid dysfunction, where stomach acid flows back into the esophagus, which can also cause nausea and discomfort. In some severe cases, such as a “thyroid storm,” nausea and vomiting become more pronounced, alongside other intense symptoms.
Associated Symptoms and Next Steps
Thyroid problems rarely present with nausea as the sole symptom. Individuals with hypothyroidism often experience fatigue, unexplained weight gain, increased sensitivity to cold, dry skin, and constipation. They might also notice hoarseness or muscle weakness. These symptoms generally develop gradually.
Conversely, those with hyperthyroidism typically exhibit symptoms such as unintended weight loss despite increased appetite, a rapid heart rate, anxiety, tremors, and increased sensitivity to heat. Frequent bowel movements or diarrhea are also common. If you experience persistent nausea, especially with several of these other symptoms, seek medical attention. A healthcare provider can conduct tests to determine if a thyroid condition is present and recommend management.