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Low Blood Sugar (Hypoglycemia or Insulin Reaction)

Published:
14-March-2005

By H. Peter Chase, M.D.

There are two emergency problems in blood sugar control for people with diabetes. The first is low blood sugar or hypogylcemia. Low blood sugar comes on quickly and must be treated by the person, family, or friends. Early treatment helps prevent a more severe reaction and possible hospitalization.

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Anytime a person has received a shot of insulin, there is a chance of a low blood sugar reaction. Thus, the family of a non-hospitalized person with newly diagnosed diabetes must know the signs and symptoms of hypoglycemia before going home the first night.

Causes Of Low Blood Sugar

Hypoglycemia (low blood sugar) occurs because the body doesn't have enough sugar to burn for energy and the level of sugar in the blood falls too low. Sometimes it is called an " insulin reaction " or just a " reaction ". Frequent causes are listed below.

  • Meals and snacks that are late or missed
  • Extra exercise that burns more sugar than usual
  • An insulin dose that is too high
  • Giving a shot into muscle which results in rapid absorption of insulin
  • Making a mistake in the drawing up of an insulin dose
  • Taking a bath or shower (or hot tub) soon after taking a shot of insulin

Prevention of low blood sugars (lows) is much wiser than having to treat the lows. When too many lows occur, the stored adrenaline (epinephrine) is depleted and then the usual symptoms of a low may not occur. In addition, the treatment (eating too much) often causes a high blood sugar and can increase the HbA1c value. Paying attention to the six causes of lows listed will help to decrease the number of low blood sugars.

The reason for low blood sugars from taking a shot just before a shower or bath is that the blood vessels in the skin dilate from the hot water and cause insulin to be rapidly absorbed. It is always wise to wait to take an insulin shot until after a shower or bath.

Symptoms Of Low Blood Sugar

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The body gives a warning when low blood sugar or insulin reaction is developing. DIFFERENT PEOPLE GET DIFFERENT WARNINGS. These signs are common warnings of an insulin reaction:

  • Hunger: the person may either feel hungry or have an upset stomach (nausea)
  • Shakiness: the person's hands or body may feel shaky
  • Sweatiness: the person may sweat more than usual (often a "cold" sweat)
  • Color: the face may become pale or red
  • Weak, anxious feeling
  • Headache
  • Confusion: the person may feel or look "spacy" or may appear "dazed"
  • Drowsiness: the person may yawn, feel sleepy, or may have trouble thinking clearly; preschoolers frequently get sleepy
  • Behavioral changes: changes in behavior are quite common; often the person may cry, act intoxicated, or act angry
  • Double vision: the person may "see double" or the pupils may get bigger; the eyes may appear glassy
  • Loss of consciousness
  • Seizure or convulsion: both loss of consciousness and convulsions occur late in the reaction; they are the result of not treating a reaction quickly enough

Initial symptoms (one through four) are due to the output of the excitatory hormone adrenaline (epinephrine is another name). Later symptoms (5 through 12) are more related to the lack of sugar to the brain. Sugar is the main source of fuel for the brain. If the low sugar continues too long, the brain can be harmed. As the brain grows very rapidly in the first four years of life, it is particularly important to prevent severe low blood sugars in young children.

Nighttime Lows

People usually wake up with symptoms (infants may just cry) when lows occur during the night. The symptoms may be the same as during the daytime, although there may be special clues.

  • Inability to sleep or waking up "alert"
  • Waking up sweating
  • Waking up with a fast heart rate
  • Waking up with a headache
  • Waking up feeling "foggy-headed" or with memory loss
  • Unusually high blood sugar or positive urine ketones (possible rebounding)

Treatment For Low Blood Sugar

The general rule is to GIVE SUGAR IN SOME FORM AS FAST AS POSSIBLE. Eventually, as a person becomes more familiar with diabetes, it may be possible to treat different reactions differently. If the reaction is not severe, do a blood sugar test first. If the level is above 60 mg/dl, it may be possible to treat the reaction with fresh fruit and solid food, rather than juice or sugar pop. Remember that it takes ten minutes for the blood sugar level to rise, and it is wise to wait for at least ten minutes to return to normal activity.

Mild Reaction (such as hunger at an unusual time, shakiness, or irritability): If possible do a blood sugar level. If below 60 mg/dl, give a glass of milk oJuly 4, 2005tion of the liquid sugar and then give solid food (crackers, sandwich, fresh fruit etc.). If the blood sugar level is above 60 mg/dl, give just solid food.

Moderate Reaction (very confused, or spacy, very pale or very shaky) Give glucose tablets or any source of simple sugar, such as sugar pop or juice. If the person is unable to feed themselves place a tube of Insta-Glucose, Glutose 15, or cake decorating gel (or whatever emergency product you have chosen) between the person's cheek and gums and tell them to swallow. Do a blood sugarlevel as soon as it is possible. Wait to give solid food until the blood sugar is shown to have risen above 60 mg/dl.

Severe Reaction (loss of consciousness, seizure, or convulsion) Glucagon should be given. Remember to do the blood sugar level as soon as possible. If the person does not improve in 10-20 minutes it may be necessary to cal 911 to get extra help. A second dose (same amount) of glucagon can also be given. In the preliminary part of the Diabetes Control and Complications Trial (DCCT), one of every 10 people (10%) receiving standard treatment had a severe reaction each year. One of four people (25%) on intensive treatment (including insulin pumps) had a severe insulin reaction each year. Thus, every family must have glucagon availible and know how to use it. It is wise to call the diabetes care provider prior to the next insulin injection for possible dose reductions.

By H. Peter Chase, M.D.
Barbara Davis Center for Childhood Diabetes
Department of Pediatrics