Reasons for Blood Sugar Swings

Upswing: Caffeine

Blood sugar can rise after drinking coffee -- even black coffee with zero calories -- thanks to the caffeine. Likewise, black tea, green tea, and energy drinks can hinder blood sugar control in people with diabetes. Each person reacts differently, so it's best to track your own responses to foods and activities. Ironically, other compounds in coffee may help prevent type 2 diabetes in healthy people.

Upswing: Sugar-Free Foods

Many foods labeled "sugar free" will raise your blood sugar level. Why? They can still have plenty of carbs from starches, fat, and fiber. Check the total carbohydrates on the back label before digging in. You should also pay attention to sugar alcohols such as sorbitol and xylitol. They add sweetness with fewer carbs than sugar (sucrose), but may still have enough carbs to your raise your blood sugar level.

Upswing: Chinese Food

When you dig into a helping of sesame beef or sweet and sour chicken, it isn't just the white rice that can cause a problem. Foods that are high in fat can cause your blood sugar to stay high longer. The same is true for pizza, french fries, and other foods that are high in both carbohydrates and fat. Check your blood sugar about two hours after you eat to know how a food affects you.

Upswing: A Bad Cold

Your blood sugar rises as your body works to fight off an illness. Drink water and other fluids to stay hydrated. Call your health care provider if you've had diarrhea or vomiting for more than two hours or if you've been sick for two days and aren't getting better. Be aware that some medicines, such as antibiotics and the decongestants used to clear your sinuses, can affect your blood sugar.

Upswing: Job Stress

Feeling overwhelmed or unhappy at work takes a toll. When you're under stress, your body releases hormones that can cause your blood sugar to rise. This is more common for people with type 2 diabetes, than those with type 1 diabetes. Learn to relax with deep breathing and exercise. If possible, change the situation that is making you feel so much stress.

Upswing: Bagels

What's the difference between eating a slice of white bread and a bagel? Bagels are packed with carbohydrates -- and calories. They have more carbs than a slice of bread. If you yearn for a bagel, choose a mini bagel. Certain foods may make your blood sugar spike even more than you would expect. Talk with your health care professional to find healthy alternatives.

Upswing: Sports Drinks

Sports drinks are designed to help you replenish fluids quickly, and some of them contain as much sugar as soda. For a moderate workout of less than an hour, plain water is probably all you need. For longer, more intense exercise, a sports drink may be appropriate. But check with your doctor first to see if the calories, carbs, and minerals in a particular sports drink are safe for you.

Upswing: Dried Fruits

Fruit is a healthy choice, but be aware that dried fruit will pack more carbohydrates in a smaller serving size. Just 2 tablespoons of raisins, dried cranberries, or dried cherries have the carbs of a small piece of fruit. Three dates give you 15 grams of carbohydrates.

Upswing: Steroids and Water Pills

One large family of drugs -- the corticosteroids, such as prednisone -- can cause your blood sugar to rise, and may even trigger diabetes in some people. Steroids are given to treat rashes, arthritis, asthma, and other conditions. Diuretics used for high blood pressure, called water pills, can also raise blood sugar levels if you have diabetes. Some antidepressants may raise or lower blood sugar.

Upswing: Cold Medicines

Decongestants that contain pseudoephedrine or phenylephrine can raise blood sugar. Cold medicines also sometimes contain sugar or alcohol. Although the sugar content is small, it is best to use products that are sugar-free and alcohol-free. Antihistamines don't cause a problem with blood sugar. Ask your pharmacist about the possible effects of over-the-counter products before you buy them.

Caution: Birth Control Pills

Birth control pills that contain estrogen can affect the way you respond to insulin. Still, women with diabetes can safely use oral contraceptives. The American Diabetes Association advises using a combination pill with norgestimate and a synthetic estrogen. The ADA also notes that birth control injections and implants are safe for women with diabetes, though they can affect your blood sugar levels.

Lower: Household Chores

Cleaning the house or mowing the lawn can have an added bonus for people with diabetes: lower blood sugar. Many of the chores you do around the house count as moderate physical activity, with plenty of health benefits. Make a point of walking around the grocery aisles or parking farther from the entrance to the store. Small amounts of exercise add up.

Lower: Yogurt

Foods that contain healthy bacteria, such as many types of yogurt, are called "probiotic." They can improve digestion and also may help you control your blood sugar. Some yogurts contain added sugar and fruit, so be careful to count the carbs. Your best choice is plain yogurt or light yogurt without added sugar.

Lower: Vegan Diet

People with type 2 diabetes who switched to a vegan, or entirely vegetable-based diet, had better blood sugar control and needed less insulin, according to one study. A boost in fiber from eating whole grains and beans might play a role, by slowing down the digestion of carbs. More research is needed to confirm the value of a vegan diet for diabetes. Talk to your health care provider before making major changes to your diet.

Promising: Cinnamon

Sprinkling your food with cinnamon can add flavor without adding salt, carbs, or calories. Some studies suggest it also can improve the body's ability to use insulin and may lower blood sugar in people with type 2 diabetes. More research is needed to confirm these promising studies, and supplements containing large doses can cause side effects. So it's best to talk with your health care provider before trying cinnamon.

Caution: Sleep

Blood sugar can dip dangerously low during sleep for some people with type 1 diabetes. It's best to check your blood sugar level at bedtime and when you wake up. A snack before bed may help. For some people, blood sugar can rise in the morning -- even before eating -- due to changes in hormones or a drop in insulin levels. Regular testing is important. One option is a continuous blood glucose monitor, which can alert you to highs and lows.

Rollercoaster: Exercise

Physical activity is a terrific health booster for everyone. But people with diabetes should tailor it to their individual needs. When you work out hard enough to sweat and raise your heartbeat, your blood sugar may spike up, then drop. Intense or endurance type exercise can make your blood sugar drop for at least 24 hours afterward. Eating a snack before you begin may help. Check your blood sugar before, during, and after you exercise.

Rollercoaster: Alcohol

Alcoholic drinks contain plenty of carbs, so at first they will raise your blood sugar. But for as long as 12 hours after drinking, your blood sugar may drop. If you drink, it's best to do so with food, and check your blood sugar. The American Diabetes Association advises no more than one drink a day for a woman and two drinks for a man. One drink is 5 ounces of wine, 12 ounces of beer, or 1 ½ ounces of liquor such as vodka or whiskey.

Rollercoaster: Heat

During the next summer heat wave, you'll be safer inside, cooled by air conditioning, during the hottest time of day. Heat makes your blood sugar more difficult to control. You should test your blood sugar often and drink plenty of water to avoid dehydration. Be aware that your medications, glucose meter, and test strips can be affected by high heat. Don't leave them in a hot car.

Rollercoaster: Female Hormones

When a woman's hormones change, so do her blood sugar levels. Keep a monthly record of your blood sugar levels to get a better idea of how your menstrual cycle affects you. Hormone changes during menopause may make it even harder to control your blood sugar levels. Talk to your health care provider about the risks and benefits of hormone replacement therapy.

Is Sugar Bad for You?

If you love sweets, don't despair. You don't have to give them up forever. Sugar will raise your blood sugar levels more quickly than other carbohydrates, but diabetes experts now say the total amount of carbohydrates is most important. Just be sure to keep your serving sizes small and take into account the total carbs and calories.

What About the Glycemic Index?

Your daily carb total, spread steadily across the day, is one key to good blood sugar control. Some people also monitor the glycemic index (GI) of foods, a rating of how individual foods raise blood sugar. Beans and whole grain breads and cereals have a lower GI than white bread or regular pasta. Juice has a higher GI than whole fruit. Want a high GI food? Eating it along with a lower GI food may help control your blood sugar.