Low Versus High Blood Sugar: Which One Poses the Greater Danger to the Human Body?

Low blood sugar poses a more immediate threat to the human body than high blood sugar, according to medical experts.

Low Blood Sugar Risks

Dr Rajiv Kovil, a diabetes and obesity specialist at Zandra Healthcare, explains that the brain depends heavily on circulating glucose. When blood sugar drops, early symptoms include hunger, sweating, trembling and palpitations. Hypoglycaemia can deteriorate within minutes if glucose falls further, causing confusion, unusual behaviour, impaired coordination, seizures or unconsciousness. The American Diabetes Association defines blood sugar below 70 mg/dL as hypoglycaemia, while levels below 54 mg/dL require immediate action. Severe or Level 3 hypoglycaemia is determined by whether a person needs another person's help due to severe impairment, regardless of the glucose reading.

High Blood Sugar Risks

High blood sugar usually develops more slowly over time. Elevated glucose over long periods can damage the kidneys, retina, nerves, heart and blood vessels. However, hyperglycaemia can become rapidly life-threatening when it progresses to diabetic ketoacidosis, known as DKA, or hyperosmolar hyperglycaemic state, known as HHS. DKA can develop over hours, while HHS often develops over days and causes profound dehydration. HHS typically involves glucose levels of 600 mg/dL or higher. People taking SGLT2 inhibitors can also develop euglycaemic DKA at modest glucose levels.

Warning Signs And Treatment

Warning signs for low blood sugar include sweating, trembling and confusion, while severe cases require glucagon and emergency help if the person cannot swallow safely. High blood sugar red flags include persistent vomiting, abdominal pain, marked thirst, frequent urination, rapid breathing and drowsiness. DKA and HHS require urgent medical assessment rather than simple home corrections. Frequent low blood sugar episodes can blunt the body's warning signals, particularly in older adults.

Context

Managing blood sugar levels requires careful balance because both extremes carry distinct medical risks. Healthcare providers emphasise stable glucose control rather than just chasing low numbers to prevent severe emergencies.