Common symptoms of type 1 diabetes, which occurs when the pancreas doesn't produce insulin, include weight loss, excessive thirst, frequent urination, fatigue, and hunger. People with type 1 diabetes may experience:

Weight loss
Dry mouth and increased thirst
Increased urination
Increased hunger
Fatigue and weakness
Blurry vision
Difficulty breathing
Skin infections
Slow-healing sores
Vaginal yeast infections
Mood swings, such as irritability, are also common symptoms of type 1 diabetes.

Untreated and progressing type 1 diabetes can lead to a dangerous complication called diabetic ketoacidosis (DKA), a complication associated with diabetes, which can cause the following symptoms:

Seek immediate medical attention if you experience the following serious symptoms:

Fruity-smelling breath
Nausea and vomiting
Abdominal pain
Lethargy
Rarely, loss of consciousness