This content originally appeared on Everyday Health. Republished with permission.

By Sheryl Huggins Salomon

Medically Reviewed by Sandy Bassin, MD of American College of Lifestyle Medicine on August 5, 2023

Blood sugar (glucose) control is crucial when you’re living with type 2 diabetes. Dips and spikes can not only make you feel cranky and sluggish, but they can also wreak havoc on your personal health. (No wonder your primary care doctor was on you about your last A1C checkup.)

The most serious effects of blood sugar swings are a higher risk for diabetes-related health complications such as stroke, heart disease, and nerve damage (neuropathy).

For the record, the American Diabetes Association (ADA) notes that you have diabetes if one of the following applies to you:

Your blood glucose after fasting (and before a meal) is 126 milligrams per deciliter (mg/dl) or higher.
Your blood glucose two hours after eating a meal is 200 mg/dl or higher.
Your hemoglobin A1C (a two- to three-month average measure of how much glucose attaches to the hemoglobin in your red blood cells) is 6.5 percent or higher.

One tricky part with type 2 diabetes is that you may not feel it when blood sugar levels are too high, according to the ADA. It feels different for everyone. “Not everyone will have the same symptoms, and some individuals will have no symptoms at all,” says Lori Zanini, RD, CDE, a Los Angeles–based and dietitian and author of The Diabetes Cookbook and Meal Plan for the Newly Diagnosed.

RELATED: The Best and Worst Foods to Eat in a Type 2 Diabetes Diet

Because blood sugar management is so important to your overall health with type 2 diabetes, you need to take action if you think your levels may be out of control, even if you’re feeling totally fine.

“Symptoms of uncontrolled diabetes may not appear until prolonged hyperglycemia (high blood sugar) has been present,” says Mary Ann Emanuele, MD, an endocrinologist, professor, and medical director of inpatient diabetes at Loyola University Medical Center in Maywood, Illinois. She adds that if your healthcare team determines your glucose isn’t well controlled, adjusting your medication with their help can make a difference.

RELATED: When Type 2 Diabetes Treatment Fails, What’s Next?

‘Controlled’ Means Different Things to Different People

There’s no one-size-fits-all recommendation for blood sugar control.

The ADA says that a “reasonable” goal for many nonpregnant adults is to aim for an A1C level of less than 7 percent. Yet some patients may be given a more stringent goal by their healthcare providers, such as 6.5 percent, if that’s reachable without harmful side effects, including hypoglycemia.

On the other hand, if you are elderly, managing other health complications, or reliant on insulin, you may be given less stringent goals. “It really becomes more important to just keep [levels] in the same place,” says Rahil Bandukwala, DO, an endocrinologist at MemorialCare South County Kidney and Endocrine Center in Laguna Hills, California. “Keeping A1C between 7.5 and 8.5 may be very reasonable for such a patient,” Dr. Bandukwala adds, echoing the ADA’s recommendations.

Because elderly people are more likely to have blood sugar that swings too far downward, with fewer warning signs, managing their glucose too tightly can put them at greater risk for hypoglycemia, says Bandukwala. When you have low blood sugar, you’re at a higher risk for becoming dizzy and falling or passing out, notes the ADA.

RELATED: 10 Warning Signs of Low Blood Sugar

How (and When) to Check Your Blood Sugar Levels

As Dr. Emanuele says, glucose monitoring can be an important tool to help you get your blood sugar under control. Typically, you would do it yourself using a glucose meter or glucometer, which analyzes a drop of blood that you draw by sticking your finger with a lancet and placing the blood on a disposable test strip that you insert into the meter. Your blood sugar goals are set by you and your doctor, but blood glucose for an adult without diabetes is below 100 mg/dl before meals and at fasting; and less than 140 mg/dl two hours after a meal, notes the ADA.

Some people will check their blood sugar daily or multiple times a day, sometimes using a continuous monitor that is worn on the body — particularly those who have type 1 diabetes or who have type 2 but take insulin. Yet how frequently a person should monitor their blood sugar is based on a number of factors, including (but not limited to) whether they’re on insulin, whether they’re taking oral medication, and how well their blood sugar is controlled and how old they are.

“It’s an individual discussion with each patient, but in general I tell my patients with type 2 diabetes whose blood sugar is controlled that they don’t need to check it every day,” says Bandukwala. “If they have a glucometer and they want to check it, then I will tell them they can do a paired reading once a week, which means a fasting (before eating) reading and then another reading one to two hours after a meal (postprandial).” Checking too often can lead to unwarranted panic over daily fluctuations, as well as unnecessary pain from too-frequent lancet pricks, he adds.

The American Academy of Family Physicians is among the organizations advising that daily glucose self-testing has no benefit in patients with type 2 diabetes who are not on insulin or medications associated with hypoglycemia.

RELATED: 10 Ways to Better Control Blood Sugar After Eating

Meanwhile, keep an eye out for these nine key warning signs and symptoms that blood sugar is too high — and talk to your doctor about whether you need to adjust your management plan.

1 — Being Extra Thirsty and Having to Urinate More Than Usual

This is a common but not-so-obvious sign of blood sugar that is too high: feeling really thirsty and needing to drink more than usual. “Excessive urination, known as polyuria, occurs when glucose builds up in your blood, and your kidneys begin working harder to get rid of the extra glucose,” says Zanini. If your kidneys can’t keep up and adjust blood sugar so that it returns to a normal level, the excess sugar is flushed out of your body through urine, she adds. You may become dehydrated and get dizzy.

RELATED: Can Chronic Dehydration Lead to Type 2 Diabetes?

2 — You’re Hungrier Than Usual but Losing Weight

Many people with uncontrolled high blood sugar find that they’re hungrier than usual, which signals a symptom called polyphagia, MedlinePlus notes. And although you’re eating more, you may be losing weight for no apparent reason if your blood sugar levels are too high, according to the Cleveland Clinic.

“Since your body is not getting energy from the preferred source, glucose, it has to turn to muscle and fat,” Zanini explains. “When your body starts breaking down muscle and fat for energy, you experience unintentional and unhealthy weight loss.” In addition to these changes in weight and appetite, you may notice weakness in your muscles and experience more frequent falls, Emanuele adds.

3 — You Feel Tiredness and Fatigue Constantly

Fatigue and extreme tiredness are symptoms of uncontrolled blood sugar, the ADA says. “Simply put, when your body is not processing insulin properly or it doesn’t have sufficient amounts of insulin, the sugar is staying in our blood rather than getting into our cells to be used for energy,” Zanini says. Also, frequent urination can lead to dehydration, which Bandukwala identifies as another contributing factor to fatigue.

RELATED: Why Does Type 2 Diabetes Make You Feel So Tired?

4 — You Have Noticeably Blurry Vision and Frequent Headaches

You may notice that your vision isn’t as clear as it used to be and that things may appear a bit blurry. High blood sugar levels can lead to swollen lenses in your eye from fluid leaking in, according to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). This changes the shape of the lens, which makes it unable to properly focus, causing blurred vision. You may also find yourself struggling at work, having difficulty driving, and suffering from frequent headaches, Emanuele notes.

RELATED: How Diabetes Can Damage Your Eyes

5 — You Develop Sores That Tend to Heal More Slowly Than Usual

Cuts, scrapes, bruises, and other wounds heal more slowly in the presence of uncontrolled blood sugar, according to the NIDDK. Diabetes causes nerve damage and affects circulation, especially in the lower legs and feet, which can delay healing because there isn’t enough blood flow to the area. Even minor wounds are more prone to infections, which can become very serious and even result in amputations of the foot. You may notice drainage seeping onto your socks or an unpleasant smell if you develop a foot ulcer, notes the American Podiatric Medical Association.

RELATED: 11 Tips to Protect Your Feet and Legs if You Have Diabetes

6 — You Notice Tingling and Numbness in Your Hands or Feet

As mentioned, uncontrolled blood sugar can cause nerve damage, also known as diabetic neuropathy. What you may notice is a tingling sensation or even numbness in your hands and feet. Some people experience pain in their hands and feet as well, and the pain is often worse at night. Though neuropathy is most common in people who have had diabetes for a long time, it can occur in anyone with poorly controlled diabetes.

RELATED: 4 Great Exercises for People Managing Diabetes-Related Neuropathy

7 — You’re Developing Blisters, Dryness, or Other Skin Changes

Small pieces of extra skin, called skin tags, may form in the creases of skin, especially if you have diabetes and you’re trying to find ways to manage your weight, notes the ADA. Dark, thick areas of soft skin (called acanthosis nigricans) may form on the back of the neck or hands, armpits, face, or other areas. These can be a sign of insulin resistance, Zanini says. Blisters, infections, dryness, itchiness, discolorations, and abnormalities of the skin can all be warning signs of high blood sugar. Check with your doctor if these skin changes develop. Conditions like acanthosis nigricans can be improved by keeping blood sugar levels in check, notes StatPearls.

RELATED: 10 Diabetes Skin Problems You Should Know

8 — You’re Getting Yeast Infections More Often Than Usual

Hyperglycemia may lead you to get more frequent genital yeast infections. The culprit is often a type of yeast (a fungus) known as Candida albicans, per the ADA. According to the Centers for Disease Control and Prevention, in females the symptoms can include: vaginal itching, redness or soreness; pain during sexual intercourse; pain or discomfort during urination; and thick, abnormal vaginal discharge. While yeast infections are common in people who don’t have diabetes, having more glucose in your blood puts you at higher risk of getting them. “The yeast feeds off the glucose, and if your blood sugar is high there’s more glucose in the urinary tract,” explains Bandukwala. Uncircumcised men with hyperglycemia are also at risk, he says.

“We’re also seeing this happen a little more now with patients who take SGLT2 inhibitors, which force the body to expel more glucose through the urine,” he adds. The U.S. Food and Drug Administration has added a warning to the prescribing information for SGLT2 inhibitors about a far more rare — and potentially fatal — genital condition, known as necrotizing fasciitis of the perineum, or Fournier’s gangrene (commonly known as a flesh-eating disease).

RELATED: What Are the Pros and Cons of SGLT2 Inhibitors for Type 2 Diabetes?

9 — Swollen or Bleeding Gums, Which Increase Your Infection Risk

Gum disease is a complication of diabetes, notes the NIDDK. It can also make diabetes harder to control, since the body’s response to infection is to release more glucose into the bloodstream, according to the ADA.

Your saliva contains glucose; and the more it contains, the more there is to feed the bacteria that combine with food in your mouth to form plaque and cause gum disease. Symptoms can include red or inflamed gums at first. If they are unaddressed, they can progress to periodontitis, which can cause your gums to pull away from your teeth, the appearance of pus or ulcers, or even tooth loss, notes the Mayo Clinic. Get your blood sugar under control and see a dental professional to prevent damage to your gums and teeth.

Additional reporting by Diana Rodriguez and Andrea Peirce.

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