While roller coasters can be thrilling at amusement parks, they’re not so great when it comes to your blood sugar levels. Also known as glucose, blood sugar is a critical source of energy for your body, according to the Mayo Clinic . When it’s either too high or too low, you can feel pretty terrible—especially if you have type 1 or type 2 diabetes .
Here’s a quick primer on how blood sugar works in people with and without diabetes.
You absorb sugar from food and beverages into your bloodstream, where insulin (a hormone from your pancreas) helps it gets into your cells to provide energy, according to the Mayo Clinic . As a backup of sorts, your liver also makes and stores its own glucose to help keep your blood sugar within a normal range.
“In general, when you don’t have diabetes, your body does a good job of regulating … glucose levels,” Amisha Wallia, M.D., an endocrinologist at Northwest Memorial Hospital, tells SELF.
But if you have type 1 diabetes, which typically appears in childhood or adolescence, your pancreas produces little or no insulin to help glucose get into your body’s cells, according to the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). That can allow too much sugar to build up in your bloodstream (hyperglycemia). If you have type 2 diabetes, which usually develops in adults, you experience high blood sugar because your pancreas either doesn’t make enough insulin or your body can’t use insulin properly, according to the NIDDK . When your blood sugar gets over 200 milligrams per deciliter, it can cause symptoms like headaches, fatigue, increased thirst, and frequent urination, per the Mayo Clinic .
On the flip side, problems managing your diabetes can also result in glucose levels that swing in the opposite direction and become too low (hypoglycemia). This is marked by blood sugar of 70 milligrams per deciliter or less and can cause symptoms like feeling shaky, tired, anxious, hungry, irritable, sweaty, or having an irregular heartbeat , according to the Mayo Clinic .
People with type 1 and type 2 diabetes might check their blood sugar several times a day at home, depending on what their treatment plan involves. This is often done with a portable electronic glucose meter that measures sugar levels with a small drop of blood, according to the Mayo Clinic , though other testing devices are available, too.
People with diabetes are most at risk for hyperglycemia and hypoglycemia, but blood sugar fluctuations can affect anyone.
If you don’t have diabetes, you can still feel like crap if your blood sugar spikes or drops, Vinaya Simha, M.D., an endocrinologist specializing in metabolism and diabetes at the Mayo Clinic, tells SELF. It’s just unlikely to actually be dangerous to your health the way it can be to a person who has diabetes. Left untreated, hyperglycemia and hypoglycemia can both be life-threatening, according to the Mayo Clinic.
Clearly you want to avoid major blood sugar spikes or dips. But there are some things that can affect basically anyone’s blood sugar, and there are others that are mainly a concern for people who have diabetes.
First up, let’s discuss four things that can affect your blood sugar whether or not you have diabetes.
1. Your last meal or snack was loaded with sugar.
Eating or drinking a bunch of sugary stuff at once can cause your blood sugar to spike, Dr. Simha says. That might confuse you if you didn’t consume a ton of obviously sugary things like cookies and candy, but carbohydrates in foods like white bread and rice also convert to glucose in your body and affect your blood sugar.
Eating or drinking too much sugar-heavy food or drink at once can lead to high blood sugar symptoms like headaches and feeling tired, Dr. Simha says. And if you have diabetes, these symptoms can occur with smaller amounts of sugary food, Fatima Cody Stanford, M.D., M.P.H., M.P.A., instructor of medicine at Harvard Medical School and obesity medicine physician at Massachusetts General Hospital, tells SELF. So, while someone without diabetes may feel terrible after eating a whole bag of cookies, it may only take one or two for someone with the condition to feel awful.
Making sure to have protein and fat with your sugar helps lower the odds that it will skew your blood sugar as much. Both nutrients can slow your body’s absorption of sugar, according to the Mayo Clinic . They can also help fill you up, decreasing the chances you’ll eat too much sugar to feel sated, Dr. Stanford says.
Beyond that, if you have diabetes, make sure to follow your medication plan, especially if you know you’re eating something with more sugar than usual, Dr. Wallia says. You should be checking your blood sugar as often as prescribed by your doctor, and if you’re having a lot of trouble controlling it, talk to a medical professional. They may have dietary or medication recommendations, or they might even provide a supplement of short-acting insulin to bring down a high blood sugar level ASAP, according to the Mayo Clinic .
2. You haven’t eaten in several hours.
If you’ve gone too long without eating, your liver can only produce so much glucose before your blood sugar drops and you start to feel shaky, weak, or get a headache , Dr. Stanford says. How long is too long between meals varies from person to person, but in general, it’s a bad idea to go more than five hours without eating, even if you don’t have diabetes, Dr. Stanford says. Some people with more sensitive cases of diabetes may need to eat every three hours or so to avoid hypoglycemia, Dr. Stanford says. If you’re not sure how often you should be eating to control your diabetes, check in with your doctor.
If it’s been hours since you last ate something and you’re feeling the symptoms of low blood sugar, you need to at least have a snack ASAP. If you don’t have diabetes, you have a bit more freedom to snack on whatever’s readily available (though you’ll want to avoid something carb-heavy to send your blood sugar to the other extreme), Dr. Wallia says. If you have type 1 or type 2 diabetes, the Mayo Clinic recommends having 15 to 20 grams of a fast-acting carbohydrate like ½ cup orange juice , then having another snack after your blood sugar levels have stabilized. In this situation, someone with diabetes wouldn’t want to reach for a snack that’s high in fat and protein, because those would actually slow their body’s absorption of sugar.
3. You drank too much alcohol.
Some forms of alcohol , like beer and hard cider, contain a lot of carbohydrates, which can cause your blood sugar to spike, Dr. Wallia says. Drinking heavily without eating can also block your liver from releasing stored glucose into your bloodstream and cause low blood sugar, according to the Mayo Clinic .
If you don’t have diabetes, your body will generally do a pretty good job of fixing this on its own, Dr. Wallia says, although eating a well-balanced meal can help get your blood sugar levels back to a normal range more quickly. If you have diabetes and you’re experiencing a blood sugar crash after drinking you may need a fast-acting carbohydrate like fruit juice to bring up your blood sugar levels. Prevention is really everything here. “With patients with diabetes, we generally tell them not to overly consume alcohol and to make sure to eat a small snack if they’re going to drink alcohol,” Dr. Wallia says.
4. You’re on corticosteroids.
Corticosteroids are drugs that mimic the effects of hormones from your adrenal glands, according to the U.S. National Library of Medicine . They’re generally used to treat inflammation and are commonly prescribed for things like rashes, asthma , and autoimmune conditions like lupus and multiple sclerosis . But corticosteroids can also increase your blood sugar levels, Dr. Wallia says.
Corticosteroid use can make it more difficult to control your diabetes, even if you were previously able to handle it just fine. And if you don’t have diabetes, using corticosteroids for a long period of time can lead to what’s known as steroid-induced diabetes or steroid-induced hyperglycemia, which is when someone without a history of diabetes develops the condition due to steroids. The thinking is that the steroids affect glucose metabolism by impairing pathways that are important for how your body regulates blood sugar and insulin.
If you’re on corticosteroids and you find that you’re having symptoms of high blood sugar, like fatigue, frequent urination , and increased thirst, talk to your doctor to see if you can switch to an effective medication without this side effect. Usually your blood sugar will eventually return to normal after you stop taking the drugs, Dr. Wallia says. Even if you can’t stop taking the corticosteroids, your doctor can help you come up with a treatment plan for the high blood sugar.
5. You threw yourself into an intense workout without preparing first.
If you suddenly go all-out in the gym without an adequate snack beforehand, your blood sugar may drop and lead to hypoglycemia, leaving you shaky and weak, Dr. Stanford says. Though anyone can feel this way if they exercise and don’t eat, it’s really more of a concern for people with diabetes who are taking insulin or other diabetes medications, according to the NIDDK .
The other potential issue is that if your body isn’t making enough insulin and your blood sugar gets too high, you might start using fat instead of glucose for energy. This can cause acids known as ketones to accumulate in your bloodstream, leading to symptoms like weakness and fatigue, excessive thirst, shortness of breath, frequent urination, fruity-scented breath, confusion, and abdominal pain, according to the Mayo Clinic .
When left untreated, this can become a life-threatening complication known as diabetic ketoacidosis. Exercising when your blood sugar is over 250 milligrams per deciliter can bring diabetic ketoacidosis on more suddenly, according to the Mayo Clinic .
Doctors typically recommend that people with diabetes who are taking insulin, doing a long workout, or trying an intense workout they’re not used to check their blood sugar at a few key intervals, according to the Mayo Clinic . That may include before you exercise, every 30 minutes during exercise, and after exercise, too. If your blood sugar dips below 100 milligrams per deciliter, you should have a snack of fast-acting carbohydrates to get your blood sugar between the 100 to 250 milligrams per deciliter range, according to the Mayo Clinic. If it goes above 250 milligrams per deciliter, don’t exercise until you’ve you brought it back down into that safe range and a ketone test shows that you don’t have ketones in your urine (you can find these over the counter or see your doctor).
And here's something that affects blood sugar but really only applies to people with diabetes.
6. You took too much or not enough insulin, or you didn’t take it at the right time.
If you have type 1 diabetes, you likely already know you need lifelong insulin therapy to regulate your blood sugar levels. This can be administered via injections or a pump you can wear that uses a catheter to feed insulin into your system, according to the Mayo Clinic . And if you have type 2 diabetes, you won’t necessarily need insulin, but it can be useful if a healthy diet and staying active aren’t enough to manage your blood sugar levels, according to the Mayo Clinic .
Either way, if you take too much insulin, too little, or deviate from your medication schedule, you can wind up with blood sugar that’s either too high or too low, Dr. Wallia says.
The solution will depend on whether your blood sugar is too high or too low. In either case, you can take the steps mentioned above to address it, like drinking fruit juice to bring up low blood sugar, or taking an emergency supplement of insulin to lower it (or otherwise following recommended steps from your doctor).
If you notice that you’re regularly taking too much or too little insulin, or you’re often not taking it when you should, talk to your doctor to figure out if there’s any way to make the process easier to follow.