Sometimes, the cause is obvious: You injected too much insulin, skipped a meal, exercised more than usual, or took too much of your oral medication. And yet at other times, low blood glucose--also known as hypoglycemia--seems to creep up on you for no reason at all.

Everyone's symptoms are somewhat different, but common ones include shakiness, sweats, sudden mood swings, irritability, hunger, fatigue, weakness, pounding heart, poor coordination, paleness, confusion, and loss of concentration. If possible, first check your blood glucose to make sure you're really experiencing hypoglycemia. If your reading shows 70 mg/dl or less, it's important to act immediately. (If you think you have a low but are not able to test, treat yourself for the low and then test as soon as you can.) Start by consuming 15 grams of a fast-acting carbohydrate (such as glucose tablets or gels or 4 ounces of fruit juice, 1 cup of skim milk, or 4 ounces of regular soda). Wait 15 minutes before testing again. If your level is still below 70, take another 15 grams. If still below 70 after consuming 30 grams of fast-acting carbs, call your doctor or head to the emergency room. A person who has lost consciousness should never be given a glucose tablet or candy or drink juice; these people require a glucagon injection and medical attention. Talk to your health care provider about whether you need a prescription for glucagon, the treatment for emergency, severe low blood glucose. If so, you will also need to make sure that the people in your life know how to administer it in an emergency. But note: Glucagon can cause vomiting, so care needs to be taken upon injection.

For less extreme lows, stash rapid-acting carbo­hydrates in a number of places, such as your car, office, purse, briefcase, and gym bag. While juice or hard candies will raise your blood glucose levels, some experts recommend specially formulated glucose tablets and gels for the best results. Here are three reasons why grabbing a tab or gel is a better choice when it comes to treating a low.

1. They're more reliable. What you eat has a lot to do with how fast your glucose rises. Many types of candy (like chocolate bars) have a high fat content, which will reduce the speed at which the sugar affects your glucose levels. (Note: If you take the drugs Precose [acarbose] or Glyset [miglitol], which also slow sugar's digestion, you should always opt for a source of pure glucose like glucose gel or tablets instead of another source of sugar.)
2. They prevent snacking. A box of glucose tabs will hardly tempt you.
3. They come pre-dosed. How many Gobstoppers does it take to raise your blood glucose? You probably don't know the answer because candy isn't portioned to treat low blood glucose levels. Glucose tablets and gels, however, make it easy to know how much to take to treat a low because they list the dose right on the package.

• Click here for a listing of Over-the-Counter Products for Treating Low Blood Glucose
• Click here for a listing of Prescription Products for Treating Low Blood Glucose