Hyperthyroidism is when your thyroid is overactive and releasing too many hormones. Weight loss, increase in appetite, diarrhea, anxiety, and rapid heartbeat are all signs of hyperthyroidism.
The most common cause of hyperthyroidism is an autoimmune disease called Graves disease, where the body attacks the thyroid and causes it to overproduce thyroid hormones. Postpartum thyroiditis can also cause hyperthyroidism, as can thyroiditis caused by an infection in the body.
4. Thyroid nodules
A nodule is simply an abnormal growth of cells, which can be either solid or fluid-filled. “Thyroid nodules are quite common,” Baker says. Most are benign, he adds, and present without symptoms. The only way you’ll know you have it is if you notice a lump in your neck or it gets picked up during a routine health exam or scan. Sometimes nodules can cause the thyroid to become overactive, but “in the majority of cases, they’re not related to under- or overactive thyroid,” Baker says.
However, some thyroid nodules can be cancerous. If you notice any lumps or swelling of your thyroid, you should always get it checked out to rule out cancer.