Unconsciousness is the main symptom of a diabetic coma, according to Mayo Clinic. The patient is alive but unable to wake up or respond to visual, aural or tactile stimulation. A diabetic coma is a potentially fatal condition if untreated.
Prior to entering a diabetic coma, a person may exhibit symptoms of either high or low blood sugar, explains Mayo Clinic. An individual with excessively high blood sugar, or hyperglycemia, may experience fatigue, rapid heartbeat, shortness of breath, and nausea or vomiting. He may also have dry mouth, increased thirst, a fruity aroma on his breath, frequent urination and stomach pain. A person with very low blood sugar, or hypoglycemia, may exhibit fatigue, weakness, shakiness, dizziness or lightheadedness, and sweating. Nausea, extreme hunger, confusion and speaking difficulty are other possible symptoms of hypoglycemia.
A person with long-term diabetes may not have any symptoms of hypoglycemia before slipping into a diabetic coma, notes Mayo Clinic. This lack of symptoms is called hypoglycemia unawareness.
A diabetic who notices symptoms of high or low blood pressure should test his blood sugar and follow his predetermined action plan based on the results, advises Mayo Clinic. If the symptoms do not subside shortly thereafter, the individual requires emergency medical care. A person who enters a diabetic coma due to high blood sugar levels may require IV fluids; insulin; potassium, sodium or phosphate supplements; or treatment of an underlying infection. A person in a diabetic coma due to low blood sugar is likely to receive a glucagon injection and intravenous dextrose. A diabetic normally regains consciousness following these treatments.