People with prediabetes, who have elevated blood sugar levels but not to the same extent as those who have diabetes, are at risk of acquiring the disease.
Prediabetes is often identified by doctors at a fasting glucose level of 100 mg/dl and diabetes at a level of 126 mg/dl.
On an oral glucose tolerance test, prediabetics would have a score between 140 and 200. Diabetics would receive a score of 200 or higher.
There are two possible ways by which diabetes results in high blood sugar levels: inadequate pancreatic insulin production or resistance to the effects of insulin elsewhere in the body.
The immune system obliterates the pancreatic cells that produce insulin in type 1 diabetes. In type 2 diabetes, the pancreas does not function properly and the body’s cells resist the effect of insulin. It produces insufficient insulin.
Supplemental insulin is required for people with type 1 diabetes to maintain healthy blood sugar levels. Despite taking non-insulin oral medicines, some type 2 diabetics may require insulin.
Regardless of the type of diabetes they have, all sufferers should keep an eye on their blood sugar levels to make sure they stay within a healthy range.
Causes;

People with diabetes who engage in a number of behaviors, such as:
excessive carbohydrate consumption
Taking fewer workouts than usual
use inadequate insulin dosages or other diabetic drugs
receiving therapy with additional drugs, such as steroids, due to stress brought on by either other illnesses or life events
When sick or under stress, diabetics may need to take more medicine to maintain stable blood sugar levels.
Additionally, the dawn phenomenon, or the hormonal surge that takes place between 4 and 5 in the morning, might raise blood sugar levels. This is the reason why morning blood sugar levels are high.
Symptoms;

Because it frequently does not manifest symptoms until blood glucose levels are quite high, hyperglycemia can be deadly.
Despite having high blood sugar, people with type 2 diabetes who have had it for a while may not exhibit any symptoms. Undiagnosed type 2 diabetes affects a large population.
The risk of diabetes-related complications such as kidney disease, eye disease, and neuropathy is raised by persistent hyperglycemia.
The following are typical hyperglycemia symptoms and signs:
increased thirst and appetite from frequent urination, as well as hazy eyesight
weight loss exhaustion wounds or sores that do not heal high urine sugar levels
slim down.