You’re doing everything right to manage your type 2 diabetes. You’re watching your carb intake, exercising regularly, and following your treatment plan. You’re avoiding bad habits — such as smoking — and taking steps to maintain your overall health.

And yet, you’re not hitting your A1C goal. Why?

The A1C is a blood test that measures your average blood sugar over the past two to three months. While your personal goal depends on several factors, the target A1C for most adults with type 2 diabetes is less than 7 percent, according to the American Diabetes Association (ADA). Your doctor uses this number to see how well your diabetes management plan is working. A high A1C, for example, may be a sign that it’s time to adjust your treatment plan.

“A lot of time, when A1C rises, a person might say, ‘What did I do wrong?’” says M. James Lenhard, MD, an endocrinologist and the medical director of Christiana Care Health System’s Diabetes & Metabolic Research Center in Newark, Delaware. “Diabetes can be frustrating, and it’s hard work to control it. Unfortunately, a lot of people feel like they have failed when they see their A1C on the rise, when the cause is often due to progression of their type 2 diabetes.”

It’s not necessarily your fault, Dr. Lenhard says. While it’s important to do everything you can to manage your type 2 diabetes, there are several factors that can up your A1C that are beyond your control.

Here are a few things that can potentially raise your A1C and what you can do to help reverse these effects.

1. Your type 2 diabetes is progressing.

Type 2 diabetes can change over time, and your treatment plan may no longer work as well as it used to, Lenhard says. If you have type 2 diabetes, your  pancreas may make insulin — a hormone needed to move glucose from the blood into cells, where it’s used for energy — but your cells don’t respond normally to it. To combat this insulin resistance, your pancreas works overtime to make more insulin to get cells to respond. Eventually, this can damage the insulin-producing cells in the pancreas, causing the organ to lose its ability to make enough insulin to keep up with your body’s needs.

“I try and remind all of my patients with type 2 diabetes that it’s a progressive disorder,” Lenhard explains. “Over time, the pancreas makes less insulin. Maintaining a healthy weight and staying active slow the process but don’t stop it.” That’s why it’s vital to work with your doctor to regularly monitor your blood sugar and A1C levels and, if needed, adjust treatment.

2. You’re stressed out.

Stress can make it difficult to control your A1C, according to Alyssa Gallagher, RD, a certified diabetes care and education specialist (CDCES) at St. Luke’s Humphreys Diabetes Center in Boise, Idaho. “Stress can absolutely play a role in diabetes progression,” she says. “It impacts your body’s ability to utilize insulin properly and contributes to insulin resistance.” It can also raise your epinephrine (aka adrenaline) and cortisol levels, causing an increase in A1C, Lenhard notes. Many people also eat more as a whole but consume less healthy food when stressed, he adds.

While it’s impossible to test for stress, Lenhard says, pay attention to warning signs — poor sleep, increased heart rate, a rise in blood pressure — particularly if you’re starting a new job, moving, getting married or divorced, or experiencing another major life event. Talk to your doctor about ways to manage stress, including exercise, yoga, mindfulness meditation, or cognitive behavioral therapy, according to the ADA.

3. You’re eating healthy foods, but you’re eating too much.

Portion control is vital to managing your A1C, Gallagher says. Watching the amount you eat helps you maintain a healthy weight, but it also helps you manage your intake of carbohydrates (which have the greatest effect on your blood sugar) and maintain healthy blood sugar levels, according to the Centers for Disease Control and Prevention (CDC).

The agency offers a guide for estimating portion sizes and recommends taking steps to control your food intake. This includes measuring portions of snacks, rather than eating straight from the bag or box, and asking your server to wrap half of your meal if you’re eating out, so you can enjoy it later. A registered dietitian or CDCES can help you develop a meal plan to help keep your blood sugar under control.

4. Your exercise plan doesn’t include strength training.

Strength or resistance training, including exercises with free weights, weight machines, body weight, or elastic resistance bands, helps your body respond to insulin better and increases the ability of your muscles to store glucose, which can help with blood sugar control, according to research. It can also help you maintain a healthy weight, reduce body fat, control blood pressure, and improve strength. The ADA recommends adults with type 2 diabetes engage in two or three sessions of resistance training per week, on nonconsecutive days.

A study published in September 2020 in the journal Medicine & Science in Sports & Exercise found that in adults with diabetes, ramping up an aerobic and resistance exercise regimen by 20 percent reduced A1C by 0.15 percent at the end of one month. Before adding strength training to your regimen or altering the workout you’re already doing, talk to your doctor about what exercises are safe for you, the ADA advises.

5. You have a diabetes-related health condition.

Over time, high blood sugar can damage your heart, blood vessels, nerves, eyes, and kidneys and lead to kidney failure, liver disease, anemia , and other health conditions. These can all affect your A1C, according to the CDC. 

“Glucose is sticky, and one of the things it sticks to is red blood cells,” says Lenhard. “Disorders that affect the amount or life span of red blood cells, like anemia or kidney disease, can affect A1C levels.” In fact, rising A1C may be a sign that you’ve developed one of these complications, he says, so talk to your doctor to see if you’re at risk. They may also be able to recommend strategies to reduce your risk.

6. You’re taking medications for another health condition.

Some prescription drugs, such as opioid pain medications and HIV therapies, can raise your A1C levels, the CDC says. If prescription medications you’re taking for other health conditions are affecting your blood sugar levels (or even the way you manage your type 2 diabetes), talk to your doctor about making changes to your treatment plan. You may need to take a more aggressive approach to compensate for how other medications are affecting you, Lenhard says. Don’t stop taking any medications — for diabetes or any other health condition — without first talking to your doctor, the CDC advises.

7. Your treatment may no longer be effective.

Because type 2 diabetes is a chronic disease, it’s likely that your treatment will need to change over time to effectively manage it, Lenhard says. An A1C that’s higher than your target may be a sign that your current treatment plan isn’t working as well as it should.

If your doctor currently has you managing your A1C with diet and exercise, it may be time to consider adding a prescription medication designed to lower A1C or improve how your body processes insulin, Lenhard notes. If you’re on an oral medication and it’s not as effective as it once was, you may need to try another one or change your dose, says Lenhard. Your doctor may also prescribe insulin or non-insulin injectables to help control your blood sugar. Once you’re on a new treatment, be sure to follow the doctor-prescribed regimen, as that’s the only way the medications will work to control your A1C, he says.

“High A1C is not healthy for anybody, but it’s particularly dangerous for the elderly and people with preexisting comorbidities, such as heart disease,” Lenhard explains. “I like to set an aggressively low A1C target for young, healthy people and a more lenient target as people age. I am happy with an A1C between 7 and 8 percent for most people in their 80s, for example, but the target is individualized.”

If your A1C level isn't meeting your target despite your efforts, you may not be doing anything wrong. Type 2 diabetes often gets worse over time, and stress or medications for other health issues can affect blood glucose and make it harder to control. 

Portion control and an exercise regimen that includes strength training might support more regular A1C levels. Regular check-ins with your doctor are crucial to help you ensure that your treatments are still effective for managing long-term blood glucose levels.