Diabetes can develop with few or no noticeable symptoms, particularly in people with type 2 diabetes. But increased thirst, frequent urination, unusual tiredness, increased hunger and blurred vision can be signs of high blood sugar and should be discussed with a health care professional.
Diabetes occurs when blood glucose, or blood sugar, becomes too high. The main types include type 1, type 2 and gestational diabetes.
Type 1 diabetes occurs when the immune system attacks and destroys insulin-producing cells in the pancreas, leaving the body with little or no insulin. Symptoms can develop relatively quickly, sometimes over days or weeks.
Type 2 diabetes develops when the body does not use insulin properly and, over time, the pancreas may not produce enough insulin to keep blood glucose within the normal range. Several factors can contribute to the condition, including genetics, family history, overweight or obesity, physical inactivity and age.
Feeling tired and unusually hungry
Persistent tiredness can occur when high blood sugar interferes with the body’s ability to use glucose for energy. Dehydration caused by frequent urination can also contribute to fatigue.
Increased hunger is another possible symptom. When blood glucose is not being used effectively by the body’s cells, a person may continue to feel hungry even after eating.
These symptoms can have many other causes, so they do not by themselves establish that someone has diabetes.
Increased thirst and frequent urination
Frequent urination and increased thirst are among the most common symptoms of diabetes.
When blood glucose becomes too high, the kidneys work to remove some of the excess glucose through urine. This process also draws more fluid from the body, increasing urination and contributing to dehydration and thirst.
Someone who notices a persistent change in how often they urinate or how much they need to drink should discuss it with a health care professional.
Dry mouth and dehydration
High blood sugar can lead to increased urination, which can cause the body to lose fluid. Dehydration may result in symptoms such as a dry mouth.
However, a dry mouth by itself is not a specific sign of diabetes and can have many other causes. Persistent thirst, frequent urination or other symptoms should be evaluated rather than used to diagnose the condition at home.
Repeated yeast infections
Frequent yeast infections can occur in people with diabetes. The Centers for Disease Control and Prevention lists recurrent yeast infections among possible symptoms of diabetes, while the Mayo Clinic notes that high blood sugar can increase the risk of infections, including vaginal yeast infections.
A yeast infection, however, does not necessarily mean a person has diabetes. Because candidiasis can have several causes, a health care professional can determine whether testing or treatment is needed.
Blurred vision
Blurred vision can occur when blood glucose levels are high. Excess glucose can cause changes in fluid in the eye’s lens, affecting its ability to focus.
Vision problems have many possible causes, so new or persistent blurred vision should not automatically be attributed to diabetes.
Other warning signs
Other possible symptoms include unexplained weight loss, slow-healing sores, numbness or tingling in the hands or feet, and repeated infections. Type 2 diabetes can develop gradually, and some people may have no symptoms at all.
The only way to determine whether someone has diabetes is through appropriate medical testing. Anyone who notices possible symptoms should speak with a health care professional rather than relying on symptoms alone.
