One of my patients has just attended for a routine eye examination. When I asked about her general health she told me she was finding it difficult to sleep, felt tired all the time and was more anxious than usual. Her friends had told her that she was also more moody than usual and had lost weight. She denied taking any medication and had no eye disease. What is going on?

This sounds like an overactive thyroid, also known as hyperthyroidism or thyrotoxicosis. This is where the thyroid gland produces too much of the thyroid hormones.

An overactive thyroid can affect anyone, but it’s about 10 times more common in women than men, and typically happens between 20 and 40 years of age.

An overactive thyroid can cause a wide range of symptoms, including:

• nervousness, anxiety and irritability
• mood swings
• difficulty sleeping
• persistent tiredness and weakness
• sensitivity to heat
• swelling in your neck from an enlarged thyroid gland (goitre)
• an irregular and/or unusually fast heart rate (palpitations)
• twitching or trembling
• weight loss

These general symptoms can occur before the typical eye symptoms and signs associated with hyperthyroidism.

Patients may mention these types of symptoms when asked about their general health during an eye examination. Note them in the clinical records, take heed of them and refer the patient to their general practitioner for a blood test.