Symptoms of low blood sugar can occur suddenly. They include:

  • blurry vision
  • rapid heartbeat
  • sudden mood changes
  • sudden nervousness
  • unexplained fatigue
  • pale skin
  • headache
  • hunger
  • shaking
  • dizziness
  • sweating
  • difficulty sleeping
  • skin tingling
  • trouble thinking clearly or concentrating
  • loss of consciousness, seizure, coma

People with hypoglycemic unawareness do not know their blood sugar is dropping. If you have this condition, your blood sugar can drop without you noticing it. Without immediate treatment, you can faint, experience a seizure, or even go into a coma.