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Blood sugar levels can fluctuate for many reasons

Medically reviewed by Last updated on Jun 7, 2022.

Many factors can cause high blood sugar (hyperglycemia) in people with diabetes. Factors include:

  • Food and physical activity choices
  • Dehydration
  • Certain medications, especially those that contain steroids
  • Skipping or not taking enough medication that lowers blood sugar
  • Taking medications incorrectly
  • Illness, infection, injury or surgery
  • Stress (both positive and negative stress)
  • Hormonal changes

Physical or emotional stress triggers the release of hormones that can cause high blood sugar levels. Menstrual periods and menopause also cause changes in the hormones that affect blood sugar levels.

Regular blood sugar testing can uncover patterns. This can help you and your health care team control your diabetes. If you experience persistent hyperglycemia, talk with your team about adjusting your diabetes treatment.

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