Symptoms usually develop rapidly

• Frequent urination
• Excessive thirst and hunger
• Sudden weight loss
• Weakness and fatigue
• Irritability
• Nausea and vomiting
• Blurred vision or any change in sight
• Drowsiness

Symptoms usually develop gradually

• Any of the above symptoms
• Tingling or numbness in legs, feet, or fingers
• Slow healing of cuts (especially in the feet)
• Frequent skin infections or itchy skin