Hypoglycemia

• Low blood sugar--also known as hypoglycemia or insulin reaction-- is a common cause of headache in diabetics. A hypoglycemia-related headache often results after missing a meal, over-exercising, drinking alcohol, or taking too much insulin or other medication.
  
  If you think your headache is related to low blood sugar, confirm it by checking your blood glucose level with your meter. If your levels are below 70 mg/dL, take one of these remedies immediately:
  
  3 glucose tablets or 1 serving of glucose gel
  1/2 cup of fruit juice
  1/2 cup of soda (not diet)
  1 cup of milk
  1 tbsp. of sugar or honey
  (However, be advised that if you are taking Acarbose or Miglitol your blood glucose levels can only be raised by taking a pure glucose tablet or gel.)
  
  After the dose, re-check your blood glucose level to make sure that it is above 70 mg/dL. Then, have a snack if your next meal is more than an hour away.
  
  

Hyperglycemia

• High blood sugar, or hyperglycemia, also can cause headaches in diabetics. High blood sugar can develop over several days or hours and can be the result of eating too much or too frequently, exercising too little, taking too little diabetes medication, stress, illness or injury.
  
  If your headache arrives in conjunction with any of those factors or your meter reading is high for you, eat a piece of vinegar soaked in bread. A 2005 study published in the European Journal of Clinical Nutrition showed that eating a piece of whole-grain wheat bread soaked in vinegar lowered subjects' blood sugar within 30 minutes. After eating the vinegar, be sure to drink plenty of water to avoid dehydration from frequent urination and take a 30-minute walk to help your body regulate your blood sugar.
  
  

When to Consult a Doctor

• While a diabetic headache is often just a sign that your blood sugar is temporarily out of balance, it may also be a sign of a serious problem. If your headache comes in conjunction with any of these symptoms, contact your doctor immediately:
  
  A sharp headache that originates behind one eye and is accompanied by blurred vision and spots or flashes of light may be a sign of glaucoma.
  
  A severe headache accompanied by dizziness, a lack of feeling in one or more limbs (numbness), slurred speech and/or drooping of one side of the face may be a sign of the onset of a stroke.
  
  A severe headache accompanied by confusion, thirst, frequent urination and dizziness can be a sign of the onset of a diabetic coma.