Blood Sugar levels w/ Type 1 diabetes?

If a type 1 diabetic has not taken any insulin in a day and a half, but has been eating as they would regulary would their blood sugar levels be high or low? And would it be dangerously so? Also, because of the blood sugar level would they light-headed or tired or something like that? Detailed answered are appreciated, thanks in advance.

Your blood sugars can become dangerously high, and cause a condition called diabetic ketoacidosis (DKA). When you do not take your insulin, your body cannot use the sugars in food for energy, so it burns fat instead. When your body uses fats, ketones--an acidic byproduct--are produced. These build up in your bloodstream, and can make you very tired and dizzy. DKA is a serios complication of diabetes, and requires stablization in the ICU.

Type 1 diabetics need insulin 24/7. Without it, BG's rise within hours, and reach a dangerous point (DKA - diabetic ketoacidosis) within 12 hours. If this is a newly diagnosed Type 1, they may still be in their "honeymoon period", where the body is still producing some insulin. So in theory they might be OK for a couple of days, but everyone is different. Symptoms of high blood glucose (hyperglycemia) are thirst, frequent urination, fatigue, sleepiness, and in advanced stages, weight loss and vomiting.

Type 1s who don't take their insulin are at risk for developing dangerously high blood sugar levels, and in the end, Diabetic Ketoacidosis. You won't necessarily feel any different if you're used to your sugars being high. You might feel extremely tired, have a splitting headache if it stays high, and you may have to pee alot more. Hope this helps!