One or more of the following symptoms may be present in someone with hyperthyroidism:
- Mood swings
- Nervousness or irritability
- Muscle weakness (in particular, the upper arms and thighs, making it difficult to lift heavy items or climb stairs)
- Hand tremors
- Rapid heart rate
- Heart palpitations
- Irregular heartbeat (atrial fibrillation).
Keep in mind that the symptoms will vary from person to person, depending on which part of the body is affected. It's also important to note that not everyone will have symptoms of hyperthyroidism.
(Click Hyperthyroidism Symptoms and Signs for a more in-depth look at the effects of an overactive thyroid. This article also explains why hyperthyroidism can lead to other medical conditions, such as osteoporosis.)