Corticosteroid injections, such as cortisone shots, are a common and effective medical treatment used to reduce localized inflammation and pain in joints or soft tissues. While highly beneficial for conditions like arthritis or tendonitis, these potent anti-inflammatory medications can temporarily disrupt the body’s glucose regulation. A resulting temporary rise in blood sugar, known as hyperglycemia, is a common and expected side effect, particularly for individuals who already manage diabetes. Understanding this temporary shift is the first step in safely managing glucose levels following the procedure.
Why Steroids Elevate Blood Sugar and How Long the Effect Lasts
The primary physiological reason for the blood sugar spike lies in how the steroid mimics the action of the stress hormone cortisol. The drug increases the liver’s production of glucose, stimulating a process called gluconeogenesis, which essentially dumps extra sugar into the bloodstream. Simultaneously, the steroid causes systemic insulin resistance, making muscle and fat cells less responsive to the insulin that is available. This dual action leaves the body with more circulating glucose and a diminished ability to move that sugar into cells for energy.
The timeline for this effect is generally predictable but depends on the specific steroid used. The rise in blood glucose typically begins within 4 to 12 hours after the injection as the medication takes effect. The blood sugar levels usually peak sharply between 24 and 48 hours post-injection, coinciding with the steroid’s maximum concentration. Depending on the steroid formulation, the elevated blood sugar can persist for three to five days, and sometimes up to 10 days, before returning to the patient’s baseline levels.
Lifestyle Strategies to Reduce Blood Sugar (Non-Medication)
For those who do not use insulin or strong diabetes medications, managing the temporary spike focuses on lifestyle adjustments. Dietary changes center on reducing the immediate glucose load placed on the body while the steroid is active. Reduce the intake of simple and refined carbohydrates, such as white bread, sugary drinks, and processed snacks, as these cause rapid blood sugar surges.
Focus on meals built around lean proteins, healthy fats, and high-fiber, low-glycemic index carbohydrates, like vegetables, legumes, and whole grains. Fiber slows the absorption of glucose, helping to maintain a steadier blood sugar profile after meals. Monitoring portion sizes for carbohydrate-containing foods limits the overall glucose released into the system.
Maintaining adequate hydration helps manage high glucose levels. Drinking plenty of water and other sugar-free liquids helps the kidneys flush out excess glucose through urine. This action helps combat dehydration, which is a common side effect of hyperglycemia.
Physical activity increases insulin sensitivity, enabling cells to take up glucose more efficiently. Light to moderate exercise, such as a brisk walk or yoga, is recommended to help lower blood sugar. However, if a blood sugar reading is above 250 mg/dL, delay strenuous exercise until the glucose level drops, as intense activity can worsen the situation in the presence of severe insulin deficiency.
Adjusting Diabetes Medications and Insulin Dosing
Individuals with pre-existing Type 1 or Type 2 diabetes who use prescription medications must approach blood sugar management in consultation with a healthcare provider. Any adjustment to existing medication dosages, especially insulin, must be directed by a physician or endocrinologist to prevent severe hypoglycemia or dangerously high blood sugar. Close medical supervision is necessary while the steroid is active.
Frequent blood glucose monitoring is necessary, often requiring checks four to six times a day, particularly during the first 48 to 72 hours when the steroid effect is peaking. This data informs temporary adjustments. Keeping a detailed log of readings, food, and medication doses is recommended for review by the diabetes care team.
Insulin Adjustment Strategies
For patients using insulin, the strategy involves increasing both basal (background) and bolus (mealtime) doses to counteract the pronounced insulin resistance. Healthcare providers may temporarily increase the total daily insulin dose by an initial 10% to 20%, or sometimes significantly more depending on the steroid dose and patient response.
For intermediate-acting steroids, doctors often recommend temporarily adding or increasing the dose of intermediate-acting NPH insulin. This timing ensures the insulin’s peak action coincides with the steroid’s peak effect, typically 4 to 6 hours after the injection.
Patients using long-acting basal insulin may require a temporary dose increase to manage sustained high glucose levels. Rapid-acting insulin doses for meals and correction factors will also need to be increased. For individuals on oral diabetes medications, a physician may temporarily increase the dose of certain drugs or add a short course of insulin if blood sugar remains uncontrolled. As the steroid effect wears off, these temporary increases must be tapered down under medical guidance to prevent low blood sugar episodes.
Warning Signs Requiring Immediate Medical Attention
While temporary hyperglycemia is expected, dangerously high blood sugar levels require immediate clinical intervention. Patients should be aware of symptoms that indicate Hyperosmolar Hyperglycemic State (HHS) or Diabetic Ketoacidosis (DKA). These life-threatening emergencies can occur in both Type 1 and Type 2 diabetes, though DKA is more common in Type 1.
Warning signs signal a medical emergency and include:
- Persistent nausea, vomiting, or abdominal pain that does not resolve.
- Severe thirst and excessive, frequent urination.
- Profound weakness or fatigue.
- Signs of severe dehydration, such as confusion, dizziness, or dry mouth.
If blood sugar readings remain consistently above 300 mg/dL despite corrective measures, or if a person experiences rapid, deep breathing known as Kussmaul breathing, seek medical help. The presence of a fruity odor on the breath is a definitive sign of DKA and requires emergency care.