Hemoglobin A1c 13.8 %: Is That High?

Is Hemoglobin A1c 13.8 % Low, Normal, or High?

HbA1c 13.8% 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 13.8% 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 result of 13.8% is a critical signal of severely uncontrolled diabetes, indicating blood glucose levels have been dangerously high for an extended period, significantly exceeding the normal range of 4.0-5.6%. This alarming figure often points to either newly diagnosed, rapidly progressing Type 1 diabetes, frequently accompanied by symptoms like severe weight loss and extreme thirst, or a long-standing Type 2 diabetes that has been critically unmanaged, potentially due to medication non-adherence or a complete lack of effective treatment. Given this extreme elevation, immediate medical assessment is imperative to prevent acute, life-threatening emergencies such as diabetic ketoacidosis (DKA) or hyperosmolar hyperglycemic state (HHS). Typical follow-up will include an urgent check of current blood glucose, ketone testing, a comprehensive metabolic panel to assess kidney function, and an immediate referral to an endocrinologist for intensive management planning. What many patients don't realize is that while a value of 13.8% is daunting, aggressive intervention often leads to a surprisingly rapid improvement in symptoms and a noticeable reduction in fatigue, thirst, and frequent urination, which can be a powerful motivator for adhering to the treatment plan. This level requires urgent, decisive action.

Hidden Risk of Hemoglobin A1c 13.8 %

An HbA1c of 13.8% 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 13.8% signifies prolonged, severe hyperglycemia, placing you at immediate and significant risk for advanced microvascular and macrovascular complications. The excessive glucose permanently damages the delicate blood vessels lining the retina, a process called glycation, increasing the likelihood of diabetic retinopathy which can lead to vision loss. Furthermore, sustained high blood sugar promotes inflammation and oxidative stress within larger arteries, accelerating the development of atherosclerosis, thereby elevating your risk for heart attack and stroke. Nerve damage, or diabetic neuropathy, is also highly probable, potentially causing pain, numbness, and even foot ulcers due to impaired sensation and poor circulation.

• 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 13.8%, 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 13.8 % 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.

A Hemoglobin A1c level of 13.8% typically points to a substantial and consistent failure to manage blood glucose over the preceding 2-3 months. This is most often due to a significant disconnect between prescribed diabetes medication dosages and the body's actual insulin needs, perhaps related to recent significant weight gain, increased carbohydrate intake that is not accounted for by medication adjustments, or inconsistent medication adherence. It could also indicate an underlying issue with the chosen diabetes medication regimen, such as inadequate oral agent strength or insufficient insulin coverage, failing to overcome a profound insulin resistance or deficiency.

At 13.8%, 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 13.8%, 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 13.8 %

Lifestyle changes at HbA1c 13.8% 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.

Immediately schedule an urgent appointment with your endocrinologist or primary care physician to discuss this critical reading. Expect an adjustment to your diabetes medication regimen, potentially including a switch to or addition of insulin therapy. Begin meticulously tracking your daily carbohydrate intake, aiming for a consistent and lower-carb approach, and increase physical activity to at least 150 minutes of moderate-intensity exercise per week. You will likely need to retest your Hemoglobin A1c in 6-8 weeks, alongside more frequent blood glucose monitoring at home to assess treatment effectiveness.

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