An ordinary cold throws the body's sugar balance into serious disarray. Stress hormones climb, cortisol and adrenaline pour into the bloodstream, and insulin resistance rises sharply. The result? Erratic, dangerous glucose readings. Conventional fingerstick monitoring tends to fail here, because the patient is exhausted, running a fever, with cold extremities — which makes drawing blood from the fingertips painful and difficult. This is where technology becomes the first line of defence. Using a Linx sensor, or any no-prick glucose monitoring device, is no longer a luxury; it has become a genuine rescue tool for taking control of the situation.

Table of Contents

1. The Physiology: Why Does Blood Sugar Rise During a Cold?
2. Technology on Your Side: The No-Prick Glucose Sensor
3. The Million-Dollar Question: Is a No-Prick Glucose Monitor Accurate?
4. Price Guide: Sensor Cost in the Sultanate of Oman and Cost Breakdown
5. Sick Day Rules
6. Frequently Asked Questions (FAQs)

1. The Physiology: Why Does Blood Sugar Rise During a Cold?

The body fights the infection and the immune system mobilises. A bacterial or viral infection places direct stress on the body's systems. The moment cold symptoms appear, the brain signals the adrenal glands to release stress hormones. In a person with diabetes, these hormones perform two especially dangerous functions:

Stimulating the liver: They drive the liver to break down its glycogen stores and release them into the bloodstream as glucose, giving the body energy to fight the infection.

Blocking insulin: They prevent insulin — whether naturally secreted or injected — from moving glucose into the cells. The cell, in effect, shuts its doors.

The immediate result is a steep spike in blood glucose, even if the patient has eaten nothing because of the loss of appetite that comes with illness. In type 1 diabetes, a shortage of insulin combined with high glucose leads to the formation of ketones, and this can progress to diabetic ketoacidosis (DKA) within hours. Spot-checking every six hours will not catch that danger. You need continuous readings.

2. Technology on Your Side: The No-Prick Glucose Sensor

When you are ill, all you want is relief. The thought of waking from sleep with a high fever and having to lance your finger to check your sugar is exactly why so many patients skip testing altogether. A no-prick glucose monitor solves that problem at the root.

The sensor — such as Linx CGM — is an extremely fine filament that sits just beneath the skin, and it measures glucose in the interstitial fluid surrounding the cells rather than directly in the blood.

Why is a sensor essential during illness?

Trend arrows: The device does not just give you a number; it tells you where your glucose is heading. An arrow pointing sharply upward means sugar is climbing fast, so you can take a correction dose before the number becomes dangerous.

Early alarms: If you slip into a hypoglycaemic episode while asleep because your eating has been disrupted, the device sounds an alarm that wakes you.

Complete comfort: Simply passing your phone or reader over your arm gives you a reading in a second — without a single drop of blood.

3. Is a No-Prick Glucose Monitor Accurate?

This question comes up constantly: is a no-prick glucose monitor really accurate, and can it be relied on to adjust insulin doses during illness?

The scientific answer: yes, it is highly accurate — but you need to understand lag time.

The sensor measures glucose in the fluid surrounding the cells, not directly in the bloodstream. Glucose travels through the blood first, then diffuses into the interstitial fluid. That process takes roughly 5 to 15 minutes.

During stable periods: The sensor reading is almost identical to a blood reading.

During rapid changes: Such as a sharp drop, or after a large correction dose, the sensor reading may trail the blood reading by about ten minutes.

When should you go back to a fingerstick even though you have a sensor?

• If you feel strong hypoglycaemia symptoms — shaking, cold sweat, a racing heartbeat — while the sensor is showing a normal number.
• If the sensor displays "Lo" (severe low) or "Hi" (severe high), meaning the value is outside the measurable range.
• If you are recovering from a severe low and want to confirm that your glucose has come back up to a safe level.

Don't leave your blood sugar to chance. Contact Linx Global now for a special discount on the fitting and setup of your first sensor, plus training on how to read the warning arrows.

5. Sick Day Rules

To protect yourself from complications, the "sick day rules" must be applied rigorously. These rules are endorsed by the world's leading health organisations, including the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC).

Rule One: Never Stop Your Basal Insulin

The single biggest mistake a person with diabetes makes when they fall ill and lose their appetite is stopping their long-acting background insulin — Lantus, Tresiba or Toujeo, for example — out of fear of going low. In reality, during illness your body is releasing glucose from the liver and needs basal insulin more than on ordinary days. Stay on your baseline dose; your doctor may increase it by 10–20% based on your sensor readings.

Rule Two: Monitor Continuously

Use a no-prick glucose sensor to follow your readings every one to two hours. Having a sensor makes moment-to-moment monitoring easy without wearing your fingertips out with repeated lancing.

Rule Three: Ketone Monitoring for the Highest-Risk Group

If your glucose stays above 250 mg/dL for more than 4 hours, you must test for ketones in urine or blood. This step is indispensable for people with type 1 diabetes. If ketones are positive, contact your doctor immediately for correction doses of rapid-acting insulin, and increase your water intake.

Rule Four: A Hydration Plan

Dehydration is the number one enemy of a person with diabetes during an infection. High glucose causes the kidneys to flush the excess sugar out in the urine, and that pulls a large volume of water out of the body with it.

• Drink a glass of water — about 250 ml — every hour.
• If you cannot eat, split your carbohydrates into liquid doses: unsweetened apple juice, warm soup, or sports drinks to replace salts. The clinical rule of thumb is 15 grams of carbohydrate per hour if your glucose is trending downward because of loss of appetite.

When should you go to the emergency room immediately?

• Persistent vomiting for more than 6 hours, or an inability to keep fluids down.
• Glucose fixed above 300 mg/dL despite taking correction doses.
• Moderate or high ketones in blood or urine.
• Difficulty breathing or severe dizziness — these are symptoms of ketoacidosis.

6. Frequently Asked Questions (FAQs)

Can I shower while wearing a no-prick glucose monitor? Yes. The sensor is designed to be water-resistant. You can shower, swim or exercise without problems, provided immersion does not exceed 30 minutes at a depth of no more than one metre, per Linx's specifications. An additional medical adhesive patch over the sensor is recommended to keep it from coming off.

How long does a single sensor last? Most currently available devices, Linx  among them, run for 15 continuous days from the moment of activation. Once that period ends, the sensor stops transmitting readings and must be replaced with a new one.

Does the sensor completely replace a fingerstick meter? About 90% of the time, yes. But you should always keep a conventional lancing device and test strips as a permanent backup plan. Fall back on a fingerstick whenever you doubt the sensor's accuracy, or during periods of rapid glucose swings.

How is the sensor fitted? Is it painful? It is fitted on the back of the upper arm. The procedure uses a built-in applicator that inserts a flexible, extremely fine filament — about the thickness of a human hair — under the skin. It takes only seconds and causes negligible pain compared with daily finger lancing.

Legal and Medical Disclaimer: The information in this article is for educational and informational purposes only and is in no way a substitute for specialist medical advice. Do not change your insulin doses or medications without consulting your treating physician or the medical team managing your case.

References

1. Centers for Disease Control and Prevention (CDC) — "Manage Diabetes When You're Sick." https://www.cdc.gov/diabetes/articles/manage-sick-days.html 

2. American Diabetes Association — "Planning for Sick Days." https://diabetes.org/getting-sick-with-diabetes/sick-days 

3. American Diabetes Association. Standards of Care in Diabetes—2026, Section 6: Glycemic Goals, Hypoglycemia, and Hyperglycemic Crises. Diabetes Care 2026;49(Suppl. 1):S132. https://diabetesjournals.org/care/article/49/Supplement_1/S132/163927/ 

4. NHS / UK diabetes services — Sick Day Guidance for Type 1 Diabetes. https://www.knowdiabetes.org.uk/resources/internal/sick-day-guidance-for-type-1-diabetes/ 

5. ADA Standards of Care in Diabetes—2026, Section 6 

6. American Diabetes Association — sick-day ketone testing frequency. https://diabetes.org/getting-sick-with-diabetes/sick-days 

7. Association of Diabetes Care & Education Specialists (ADCES) — danatech CGM Glossary, "Lag Time." https://www.adces.org/education/danatech/glucose-monitoring/continuous-glucose-monitors-(cgm)/cgm-101/cgm-glossary/lag-time 

8. Alva S, et al. "Accuracy of a 14-Day Factory-Calibrated Continuous Glucose Monitoring System With Advanced Algorithm in Pediatric and Adult Population With Diabetes." J Diabetes Sci Technol. 2022;16(1):70–77. https://pubmed.ncbi.nlm.nih.gov/32954812/

9. Oregon Health & Science University (OHSU) — Sick Days and Diabetes Self-Care Guidelines. https://www.ohsu.edu/schnitzer-diabetes-center/sick-days-diabetes 

10. Nebraska Medicine — Sick Day Guidelines for Type 1 Diabetes (PDF). https://www.nebraskamed.com/sites/default/files/documents/Diabetes/10_9212%20Sick%20Day_Type%201.pdf 

11. Vancouver Coastal Health — My Sick Day Plan for Type 1 Diabetes (PDF). https://www.vch.ca/sites/default/files/import/documents/VGH-Diabetes-Centre_My_Sick_Day_Plan_Type_1.pdf