Hypoglycemia or an abnormally low blood sugar level is a common complication among diabetic patients. People with diabetes have poor control of their blood sugar level due to either a relative or absolute deficiency in insulin, the hormone that helps the body utilize glucose effectively.

Hypoglycemia may also occur in other disease states such as hormonal disorders or Addison's disease and due to starvation, malnutrition or poisoning.

The symptoms of hypoglycemia mainly arise due to over activity of the sympathetic nervous system which occurs in response to a fall in blood sugar. Some examples of such symptoms include:

• Tremors - The patient often complains of feeling shaky or weak
• Sweating - There may be intense sweating, with the skin appearing cold and clammy
• Palpitations - There may be a rapid heart rate and palpitations
• Anxiety, depression, tearfulness and feeling of dread
• Restlessness
• Dilated pupils
• A sensation of pins and needles or tingling in the extremities such as the fingers and toes

Other symptoms that may manifest

As the blood sugar levels fall, the hunger centre in the brain may be stimulated, giving rise to intense hunger and noises made by the stomach called borborygmus. Nausea and sometimes retching can also result.

In newborn babies with hypoglycemia the symptoms include irritability, crying, jitters and jerky movements, difficulty in breathing, sweating, cold extremities (hands and feet), increased sleepiness, bluish discoloration of the hands and feet (cyanosis), refusal to feed and convulsions.

The brain

The brain is especially sensitive to a decreasing blood sugar level. Since the brain has a very minimal glucose reserve, it depends on the continuous availability of glucose and symptoms may manifest soon after the blood sugar drops. Some of these include:

• Confusion or disorientation
• Headache
• Dizziness and light headedness
• Blurred or double vision
• Slurred speech
• Difficulty in concentrating and loss of judgement
• Impaired coordination of movement
• In cases of severe hypoglycemia, there may convulsions or seizures, loss of consciousness and even coma and death. Seizures or coma can also cause irreversible brain damage.