Signs & Symptoms of High Sugar Level in the Blood

Glucose--or blood sugar--is the main source of energy in the human body. When blood sugar levels are too high, it is a sign your body is not using the sugar properly, according to the National Library of Medicine. A high blood sugar level, called hyperglycemia, often develops in people who have diabetes, although it can develop independent of that condition as well 1. Your blood sugar level can be determined with a simple blood test. Knowing the signs and symptoms of a high sugar level in the blood may help you head off any potential health problems that could result.

Excessive Hunger

Excessive hunger is often a sign of a high blood sugar level, according to the American Diabetes Association 1. People with hyperglycemia may be constantly or frequently hungry despite eating regularly.

Increased Thirst and Urination

An excessive thirst that is difficult to quench is another sign that your blood sugar level is too high, according to the Joslin Diabetes Center at Harvard University. You may constantly be thirsty despite an adequate fluid intake. In conjunction, you may also notice an increase in your urine output.

Dry Mouth

When blood sugar levels are too high, you can also develop a dry mouth, Joslin Diabetes Center reports. A dry mouth can contribute to the feeling of always being thirsty and can persist despite proper fluid intake.

Slow-Healing Wounds

A person with hyperglycemia may notice that minor cuts, scrapes and other skin wounds are healing more slowly than they once would have, according to the National Library of Medicine.

Frequent Infections

A high blood sugar level can also cause a person to be sick more often, with frequent and chronic infections, the Joslin Diabetes Center reports.

Weight Loss

Another sign of hyperglycemia is weight loss, according to the National Library of Medicine. Weight loss can occur despite a healthy or even an above-average appetite, which can also result when blood sugar levels are high.


In severe cases, your blood sugar level can become so high that a serious condition called ketoacidosis can develop, according to the McKinley Health Center at the University of Illinois. Symptoms of the condition include fruity-smelling breath, an extremely dry mouth, nausea and vomiting, and shortness of breath. Ketoacidosis is a potentially life-threatening condition requiring immediate medical attention.