Diabetes and thyroid disease are both endocrine, or hormone, problems. When thyroid disease occurs in someone with diabetes, it can make blood glucose control more difficult.
The thyroid is a butterfly-shaped gland in your lower neck just beneath your skin. It regulates your body’s metabolism, the processes of using and storing energy, by releasing a substance called thyroid hormone. If it produces too much thyroid hormone, your metabolism quickens (hyperthyroidism), too little and your body functions slow down (hypothyroidism).
Hyperthyroidism. When your metabolism quickens, your medicines go through your body quicker. Your blood glucose level may rise because your usual dosage does not stay in your body long enough to control it.
Hyperthyroidism and low blood glucose can be hard to tell apart. If you are sweating and having tremors from hyperthyroidism, you may think you have low blood glucose and eat extra food, causing your blood glucose to rise. Using your glucose meter to verify low blood glucose levels can help you avoid this problem.
Hypothyroidism. When your metabolism slows, your blood glucose level may drop because your diabetes medicine doesn’t pass through your body as quickly as usual and so stays active longer. In hypothyroidism, it is often necessary to reduce your dose of diabetes medicines to prevent low blood glucose.