How do follicular adenoma thyroid nodules affect your body?

Often not at all. If they do not produce excess thyroid hormone, they have minimal effect on the rest of the body unless they are actually follicular cancers, and spread to other parts of the body. If they do overproduce thyroid hormone, typical hyperthyroid symptoms may occur: feeling hot, shaky, sweaty, heart pounding, poor sleep, poor concentration, bone loss, weight loss or weight gain., ^ appetite.
No effect usually. Most follicular nodules do not effect your body unless they are very large and compress the trachea or esophagus.
They usually don't. Unless the adenoma is causing hyperthyroidism, follicular adenomas do not have symptoms. The problem is that they must be distinguished from follicular cancer. Although some centers are doing molecular typing to tell them apart, surgery is often required.
They don't. Follicular adenomas must be distinguished from follicular cancer, but the nodules themselves don't produce additional hormones that will cause symptoms.