Hello and thank you for your inquiry. Based on the symptoms you describe, you possibly have hyperthyroidism, a result of excess thyroid hormones produced by your thyroid glands. These excess hormones increase your metabolism which cause the symptoms you currently experience.

Other symptoms may include weight loss, diarrhea, intolerance to heat, irregular periods and tremors in your hands. The neck lump you describe is likely your enlarged thyroid glands and it is possibly compressing structures in your neck, causing your difficulty in swallowing.

The enlargement may additionally cause pain and even difficulty breathing when it becomes too large. However, thyroid pain in association with hyperthyroidism may also indicate subacute thyroiditis where your thyroid glands are inflamed due to a viral infection.

There are various causes for hyperthyroidism. They include Graves disease, toxic multinodular goitre, toxic adenoma and thyroiditis. Rarely, hyperthyroidism is caused by thyroid cancer. In order for your doctor to find out the cause of your symptoms for appropriate treatment to be chosen, your doctor has to evaluate your symptoms and medical history, perform a physical examination, run blood tests to evaluate your thyroid hormone levels and perform an ultrasound scan for your thyroid glands.

There are various treatment options and they depend on the underlying diagnosis. Options include using anti-thyroid medications, radioiodine therapy, surgical removal of the glands and also beta-blockers to slow the heart rate for those who need it. Note that some of these treatments would leave you permanently hypothyroid which then requires you to be on lifelong thyroid hormone supplementation.

I recommend that you consult your general practitioner to undergo the appropriate tests, get properly diagnosed and receive appropriate treatment. With the right treatment, the symptoms will be kept under control effectively. This will also help prevent disease progression and further complications from this condition.