Diabetes Symptoms

Diabetes Symptoms

The two types of diabetes have very similar symptoms. The first symptoms are related to the direct effects of high blood sugar levels. When the blood sugar level rises above 160 to 180 mg/dL, sugar spills into the urine. When the level of sugar in the urine rises even higher, the kidneys excrete additional water to dilute the large amount of sugar. Because the kidneys produce excessive urine, people with diabetes urinate large volumes frequently (polyuria). The excessive urination creates abnormal thirst (polydipsia). Because excessive calories are lost in the urine, people lose weight. To compensate, people often feel excessively hungry. Other symptoms include blurred vision, drowsiness, nausea, and decreased endurance during exercise.

Type 1: In people with type 1 diabetes, the symptoms often begin abruptly and dramatically. A condition called diabetic ketoacidosis may quickly develop. Without insulin, most cells cannot use the sugar that is in the blood. Cells still need energy to survive, and they switch to a back-up mechanism to obtain energy. Fat cells begin to break down, producing compounds called ketones. Ketones provide some energy to cells but also make the blood too acidic (ketoacidosis). The initial symptoms of diabetic ketoacidosis include excessive thirst and urination, weight loss, nausea, vomiting, fatigue, and—particularly in children—abdominal pain. Breathing tends to become deep and rapid as the body attempts to correct the blood's acidity (see Acid-Base Balance: Acidosis). The breath smells like nail polish remover, the smell of the ketones escaping into the breath. Without treatment, diabetic ketoacidosis can progress to coma and death, sometimes within a few hours.

Type 2: People with type 2 diabetes may not have any symptoms for years or decades before they are diagnosed. Symptoms may be subtle. Increased urination and thirst are mild at first and gradually worsen over weeks or months. Eventually, people feel extremely fatigued, are likely to develop blurred vision, and may become dehydrated.

Sometimes during the early stages of diabetes, the blood sugar level is abnormally low, a condition called hypoglycemia (see Hypoglycemia).

Because people with type 2 diabetes produce some insulin, ketoacidosis does not usually develop. However, the blood sugar levels can become extremely high (often exceeding 1,000 mg/dL). Such high levels often happen as the result of some superimposed stress, such as an infection or drug use. When the blood sugar levels get very high, people may develop severe dehydration, which may lead to mental confusion, drowsiness, and seizures, a condition called nonketotic hyperglycemic-hyperosmolar coma.