Hemoglobin A1c 13.9 %: Is That High?

Is Hemoglobin A1c 13.9 % Low, Normal, or High?

HbA1c 13.9% is considered very high and indicates that blood sugar has been severely elevated over the past two to three months. The American Diabetes Association defines diabetes at HbA1c of 6.5 percent or above, and at 13.9% your blood sugar has been far above target for an extended period. This result requires urgent medical attention. While this number is serious, it is important to know that with proper treatment and support, significant improvement is possible.

An A1c of 13.9% represents a critical medical situation, signaling severely uncontrolled diabetes and sustained, dangerously high blood glucose levels over the past two to three months. This value, nearly three times the upper limit of the normal range (4.0-5.6%), indicates an urgent need for intervention to prevent acute complications like diabetic ketoacidosis (DKA) or hyperosmolar hyperglycemic state (HHS), and to mitigate long-term damage to vital organs. Such an extreme elevation most commonly arises from newly diagnosed, often advanced, Type 1 or Type 2 diabetes, or a complete and prolonged breakdown in existing diabetes management, perhaps due to significant non-adherence to prescribed medications, a rapid progression of the disease, or an unaddressed underlying stressor. Immediate and comprehensive medical evaluation is essential, involving an urgent appointment with an endocrinologist, detailed blood tests to assess organ function, and potentially C-peptide or autoantibody tests to refine diagnosis. Intensive diabetes education and an immediate review and probable adjustment of your treatment regimen, very likely including the initiation or intensification of insulin therapy, will be prioritized. It's vital for individuals receiving this A1c result to understand that while this figure is alarming, it is not a permanent state; dramatic improvements are very possible, often relatively quickly, with dedicated management and consistent effort alongside your healthcare team.

Hidden Risk of Hemoglobin A1c 13.9 %

An HbA1c of 13.9% puts your body under significant stress, even if you have adapted to how it feels. At this level, blood sugar has been running so high for so long that serious complications are either developing or accelerating. The urgency is real, even if you do not feel dramatic symptoms.

A Hemoglobin A1c of 13.9% signifies prolonged, severe hyperglycemia, significantly elevating the risk for microvascular complications. Specifically, the chronic overexposure to high blood glucose levels leads to advanced glycation end products (AGEs) damaging the small blood vessels in the kidneys (diabetic nephropathy), eyes (diabetic retinopathy, potentially leading to blindness), and nerves (diabetic neuropathy, causing pain, numbness, and increased risk of foot ulcers and amputations). This level also puts undue stress on the cardiovascular system, increasing the likelihood of heart attack and stroke due to accelerated atherosclerosis.

• At this HbA1c level, your estimated average blood sugar has been approximately 298 mg/dL, nearly three times the normal average
• The risk of diabetic retinopathy (eye damage) increases exponentially above HbA1c 8.0%. At 13.9%, annual eye exams are critical
• Kidney damage is a major concern. The National Kidney Foundation reports that sustained high blood sugar is the leading cause of kidney failure
• Nerve damage (neuropathy) progresses rapidly at this HbA1c level, potentially causing permanent numbness, pain, or weakness in the extremities
• Cardiovascular risk is severely elevated. People with poorly controlled diabetes face dramatically higher rates of heart attack and stroke
• Wound healing is impaired and infection risk is increased, making even minor cuts and injuries a greater concern

What Does a Hemoglobin A1c Level of 13.9 % Mean?

HbA1c measures how much glucose has bonded to the hemoglobin in your red blood cells. Since red blood cells live about three months, HbA1c captures a rolling average of your blood sugar over that period. It is one of the most important tests for managing diabetes.

Achieving an A1c of 13.9% typically indicates a failure in consistent diabetes management. Most likely causes include significant and sustained dietary indiscretion, such as chronic high intake of refined carbohydrates and sugars, coupled with insufficient physical activity. Non-adherence to prescribed diabetes medications, including oral agents or insulin, is also a major contributor; perhaps doses are missed, or the wrong types are being used. Less commonly, an underlying acute illness or significant stress event could temporarily push glucose levels this high, but sustained values suggest a breakdown in daily management routines.

At 13.9%, your estimated average blood sugar has been approximately 298 mg/dL. Normal average blood sugar is around 100 mg/dL, and the ADA target for most people with diabetes is an HbA1c below 7.0 percent, which corresponds to roughly 154 mg/dL. Your reading indicates that blood sugar has been running about three times higher than normal.

This level of glucose elevation means that your body's insulin system is severely impaired. In type 2 diabetes, this usually means a combination of advanced insulin resistance and declining insulin production from the pancreas. In type 1 diabetes, it indicates that insulin therapy needs significant adjustment.

At 13.9%, excess glucose is constantly circulating in your blood, bathing your blood vessels, nerves, and organs in sugar. This creates a toxic environment that accelerates damage throughout the body. The longer blood sugar stays at this level, the more harm accumulates. However, bringing HbA1c down even partially provides immediate protective benefit. Reducing from 12.0 to 9.0 percent, while still above target, dramatically reduces complication risk.

Lifestyle Changes for Hemoglobin A1c 13.9 %

Lifestyle changes at HbA1c 13.9% are important but should happen alongside medical treatment, not instead of it. At this level, lifestyle alone cannot bring blood sugar to a safe range. However, the habits you build now will determine how well your treatment works and how quickly your numbers come down.

Immediate and aggressive management is required. Your next step is a follow-up appointment with your endocrinologist or primary care physician within one week to discuss a significant medication adjustment, likely involving adding or intensifying insulin therapy. Simultaneously, commit to a meticulously planned low-carbohydrate diet, focusing on non-starchy vegetables and lean proteins, and aim for at least 30 minutes of moderate-intensity exercise daily. Monitor blood glucose levels at least four times per day, tracking pre-meal and two-hour post-meal readings to identify patterns and report them to your doctor at your next visit.

Physical activity is one of the fastest ways to help lower blood sugar. Exercise moves glucose from the blood into muscles, and this effect lasts for hours. The ADA recommends 150 minutes per week of moderate activity. Walking after meals is a great starting point because it directly addresses the blood sugar spike that follows eating. Even 10 to 15 minutes of walking after each meal can make a noticeable difference in glucose readings.

Weight loss, if applicable, has a powerful impact on insulin resistance. Every pound lost improves insulin sensitivity. A target of 5 to 10 percent body weight loss is realistic and meaningful. Focus on sustainable changes rather than extreme diets.

If you smoke, stopping is essential. Smoking worsens every diabetes complication and increases insulin resistance. Your doctor can help with cessation support.

Sleep and stress both affect blood sugar significantly. Aim for seven to nine hours of sleep per night. Chronic stress raises cortisol, which raises blood sugar. Building even simple stress management practices into your day supports your treatment plan.

Written by

Ernestas K.

Clinical research writer specializing in human health, biology, and preventive medicine.

Reviewed against ADA, CDC, NIH, WHO, Mayo Clinic guidelines · Last reviewed March 20, 2026