If you have had a total thyroidectomy or a completion thyroidectomy to remove the rest of your thyroid gland at a second operation, you are at risk of developing a low blood calcium after your surgery.
This is due to 4 very small glands adherent to your thyroid being temporarily (or infrequently permanently) disrupted by dissecting them off the thyroid gland at your operation. They have an important role controlling your calcium levels, and if they stop working you can experience a tingling sensation around your lips and fingertips.
If this is left untreated, you can then get cramps and muscle weakness. If left completely untreated it can adversely affect how your heart beats. If you treat it at the first signs of tingling these more dangerous effects will be avoided.