What does diarrhoea feel like with hyperthyroidism?

An overactive thyroid can speed up the movement of food through the gut, leaving less time for water to be absorbed. You may also notice abdominal rumbling, cramps, more frequent bowel movements, heat intolerance, sweating, shakiness, a racing or irregular heartbeat, trouble sleeping, or unplanned weight loss. These symptoms vary, and diarrhoea alone does not establish a thyroid diagnosis.

Replace lost fluid with frequent sips of water or oral rehydration solution. Keep a brief record of stool changes, palpitations, temperature sensitivity, sleep, appetite, and weight changes. Arrange a medical appointment if the pattern persists or occurs with other signs of thyroid overactivity. Blood tests can check thyroid function, and treatment is chosen according to the cause and your overall health.

Seek urgent care for chest pain, fainting, severe breathlessness, confusion, a very fast or irregular heartbeat, or inability to keep fluids down. Prompt medical advice is also sensible when diarrhoea causes dizziness, very dark urine, or unusual weakness. A sudden worsening of tremor, fever, agitation, or marked heat intolerance needs emergency assessment.

Ask whether thyroid blood tests are appropriate, whether any current medicine or supplement could be worsening diarrhoea, and how to monitor your pulse and hydration. Tell the clinician about eye changes, neck swelling, palpitations, recent weight change, and family thyroid history.