Can a simple fever be that bad for a diabetes patient?

Abstracted from Dr. Bernstein’s book “Diabetes Solution”
© 2007 by Richard K. Bernstein, M.D.

No doubt you’ve heard the advice, “Drink plenty of fluids,” for a fever.  This is because fever causes considerable fluid loss through the skin as perspiration. Your loss of fluid can be difficult to estimate, so your physician may want to assume that you’d require 1–2 more quarts of fluid daily than you’d normally need. Ordinarily, a mild fever helps to destroy the infectious agent (virus or bacteria) that caused the fever.  The tendency to sleep out fever may also be beneficial.

For a diabetic, however, the somnolence that you experience with fever may discourage you from checking your blood sugar, covering with insulin, drinking adequate fluid, and calling your physician every few hours. If you don’t have someone awaken you every 20 minutes, you should use aspirin, acetaminophen (Tylenol), or ibuprofen (Advil or Motrin), in accordance with your doctor’s instructions, to help fight the fever. Beware, however, that aspirin can cause false positive readings on tests for urinary ketones, so don’t even test for ketones if you are using aspirin. Never use aspirin or ibuprofen (or any of the nonsteroidal anti-inflammatory drugs, NSAIDs) for fever in children because of the risk of Reye’s syndrome. Excessive doses of aspirin or NSAIDs (naproxen, ibuprofen, and many others) can cause severe hypoglycemia. If at all possible, try not to use NSAIDs, as the combination of these drugs with dehydration can cause kidney failure. Acetaminophen can be highly toxic if used in doses greater than those indicated on the package label.

If you have fever, the guidelines for blood sugar control and replacement of fluid are almost the same as indicated previously for vomiting. There is one difference, however. Since there is very little electrolyte loss in perspiration, it’s not necessary to add salts to the fluid you consume if you’re not vomiting or experiencing diarrhea. Certainly there is no reason not to eat if you feel hungry—but if you want to eat, cover your meals with your usual dose of insulin or ISA. If you’re hungry for only a small meal, eat half or a quarter of your usual protein and carbohydrate, and cover it with only half or a quarter of your usual dose of insulin or ISA.


Like hypoglycemia, dehydrating illness can be life-threatening to a diabetic.

Encourage the people you live with to read this chapter carefully. The supplies mentioned should be kept in locations known to all. Phone your physician at the first sign of fever, diarrhea, or vomiting. The chances are that he/she would much rather be contacted early, when dehydration and loss of blood sugar control can be prevented.  Emergency situations make treatment more difficult, so you can make your life and your physician’s a bit easier by phoning before major problems occur.

Your physician will probably ask you whether your urine shows ketones, so use the Ketostix whenever you urinate before you call. Also, let your doctor know if you have taken any aspirin in the prior 24 hours, as this can cause a false positive Ketostix reading. If you are not eating, your urine will certainly show “moderate” ketones. Your physician should therefore only be concerned if it shows “high” ketones combined with high blood sugars (160 mg/dl or above). Always report your recent blood sugars when you phone your physician.


Most infections can cause elevation of blood sugars, from an infected toe to infected tonsils to infected heart valves. Most infections cause symptoms that are recognizable, such as burning upon urination if you have a urinary tract infection, coughing if you have bronchitis, and so on. So you’ll get pretty prompt warning from your body that you should immediately contact your physician. If you have type 2 diabetes or early type 1, you certainly don’t want your blood sugars to get so high that your remaining beta cells are destroyed. My friend Jay put off visiting a urologist until his blood sugars got so high that his type 2 diabetes became type 1 diabetes and he required 5 daily insulin injections. Occult, or hidden, infections will not become readily apparent unless you notice that your blood sugars have become unreasonably high and you have the good judgment to contact your doctor.

By far the most common type of occult infection is that family of infections that affect dental structures. This includes infections that affect root canals, gums, and jawbones. A history of elevated blood sugars over a period of years predisposes diabetics to such infections; these infections, in turn, predispose diabetics to high blood sugars and severe insulin resistance.

If one of my patients calls our office and complains of recent onset high blood sugars but no apparent accompanying infection (no coughing, for instance), we ask if she or he is reusing insulin syringes and contaminating insulin, making injections relatively ineffective (see page 257). If the answer is no, then we recommend a visit to the dentist immediately to search for an oral infection.

Among the things that your dentist should do are to examine your gums very carefully and to tap every tooth to see if one or more is tender.  He or she should also touch each tooth with a chip of ice. Pain upon exposure to cold is the most common overt symptom of infection in the tooth or jawbone, in my experience. We have had patients with dentists who refused to do this and we’ve had to instruct the patients to find better dentists. This is one of those many cases of being a good, educated health care consumer in order to get proper treatment for your diabetes. In each case, when a new dentist performed these tests, a problem was found. If your dentist does find a problem, he or she will probably refer you to an endodontist or periodontist to treat the infection.

Even after such dental infections have been successfully treated, however, blood sugar elevations frequently continue for many months.  If this occurs, an appropriate antibiotic should be prescribed and continued until blood sugars remain at their preinfection level. Many people require continuation of antibiotics for as long as a year after treatment to prevent further blood sugar increases. When using oral antibiotics, always take a probiotic every day,* at least 2 hours before or after the antibiotic, to replace gastrointestinal bacteria killed by the antibiotic.

To help prevent dental infections, it is wise to arrange with your dentist for tartar to be removed from your teeth ultrasonically every three months. You should also brush your teeth at least twice daily and after meals floss from between your teeth any food that remains there.  If your teeth are too tightly spaced for flossing, try Stimudent, which is a specially designed toothpick with a triangular cross-section. Push it between your teeth with the base of the triangle against your gum. An even easier product to use is Doctor’s BrushPicks, available at most pharmacies.

* My current favorite probiotic is saccharomyces boulardii (brand name Florastor). It is available at most pharmacies.