Low blood sugar, also known as hypoglycemia, occurs when blood sugar levels drop below normal. A blood sugar level below 70 mg/dL (3.9 mmol/L) is considered low and can be harmful. Severe low blood sugar is below 54 mg/dL and can cause fainting or unconsciousness. Symptoms of low blood sugar include nervousness or anxiety, irritability or confusion, dizziness, hunger, and shakiness. If left untreated, low blood sugar can lead to seizures, coma, and even death.

On the other hand, high blood sugar, also known as hyperglycemia, occurs when blood sugar levels are too high. Blood glucose levels may become very high, greater than 600 mg/dL (33.3 mmol/L) without ketoacidosis. Symptoms of high blood sugar include increased thirst, frequent urination, blurred vision, tiredness or weakness, headache, nausea and vomiting, shortness of breath, stomach pain, fruity breath odor, and a very dry mouth. If left untreated, high blood sugar can lead to serious health problems such as heart disease, stroke, kidney damage, nerve damage, eye damage, and skin problems.

It is important to monitor blood sugar levels regularly and take appropriate action to bring them back to normal levels. If you experience symptoms of low or high blood sugar, seek medical attention immediately.