Diabetic people could have too much or too little glucose in the blood.
Carbohydrates--sugary or starchy foods such as chocolates, cakes, biscuits, bread and potatoes, or fruit and jam--send up the levels of sugars in the blood. Under normal circumstances, a proper balance is soon restored through the action of insulin. If the body's output of insulin is too low, or the insulin produced is ineffective to turn glucose into energy, the blood glucose remains high. This is how hyperglycaemia (high blood sugar) is caused.
Excess glucose in the blood needs to be excreted. Consequently, one test for diabetes is to measure the level of glucose in the urine. The most prominent symptoms of this imbalance are a need to urinate often, excessive thirst and a dry mouth. Other symptoms include weight loss, itching, hunger, tiredness, recurrent infections, problems with vision, and, in severe cases, coma.
Too little glucose, resulting in low blood sugar, or hypoglycaemia, can also result in a coma. This occurs when a person with diabetes has injected too much insulin, eaten too little food, or has exercised without extra food. Taking small amounts of sugar, sweet juice, or food with sugar will usually help the person feel better within 10-15 minutes.
Symptoms of hypoglycaemia include nausea, sweating, weakness, faintness, confusion hallucinations, headache, cold sweat, piloerection (erection of the hair), hypothermia (a low body temperature), irritability, bizarre behavior and fainting. Prolonged hypoglycaemia can result in complete loss of consciousness, convulsions, coma and brain damage.
Complications of diabetes frequently include blindness, heart disease, kidney failure, and circulation problems in the extremities.