Hyperglycemia or high blood sugar causes several symptoms, particularly if the condition persists in the long-term (chronic hyperglycemia). Most cases of acute or temporary hyperglycemia do not present with symptoms. Some of the symptoms associated with both acute and chronic hyperglycemia are described below, with the first three forming the classic hyperglycemic triad.

• Polyphagia – Polyphagia describes increased and excessive hunger. This is caused by a low blood sugar level, which may be brought on by taking too much anti-diabetes medication. Missing a dose of insulin following a meal and too much physical activity are other factors that may cause low blood sugar and trigger increased hunger.
• Polydipsia – This refers to excessive thirst and is usually accompanied by a dry mouth.
• Polyuria – This refers to the passage of an excessive and abnormally large volume of urine.

Both polydipsia and polyuria occur when a high blood glucose level means glucose moves into the urine taking water, salt and minerals along with it.

Other classic symptoms of hyperglycemia include the following:

• Blurred vision
• Fatigue
• Weight loss
• Poor or delayed wound healing
• Recurrent infections such as thrush or swimmer’s ear.
• Dry or itchy skin
• Erectile dysfunction
• Cardiac arrhythmia (irregular heart rate)
• Stupor
• Seizures
• Coma