A cortisone shot, a localized injection of corticosteroid medication, can cause a temporary but significant rise in blood sugar levels, known as hyperglycemia. Corticosteroids are synthetic versions of hormones that the body naturally produces, and they are highly effective at reducing inflammation and pain in a targeted area. While the injection is local, the medication is absorbed into the bloodstream, where it exerts systemic effects on the body’s glucose regulation system. This effect occurs regardless of whether a person has a pre-existing diagnosis of diabetes, making awareness important for anyone receiving the treatment. The temporary change in glucose metabolism necessitates careful monitoring and management.
The Mechanism: How Cortisone Shots Affect Blood Sugar
Corticosteroids increase blood sugar through two primary, interconnected actions on the body’s metabolism. The medication mimics stress hormones, signaling the body to make more energy available. This signal targets the liver, causing it to increase hepatic glucose production by releasing a higher volume of stored glucose into the bloodstream than usual.
Simultaneously, the drug induces a temporary state of insulin resistance throughout the body. Insulin allows glucose to move from the bloodstream into cells for energy. When resistance occurs, cells become less responsive, and muscle and fat cells struggle to absorb circulating glucose, which accumulates in the blood. This dual action—increased liver production and decreased cellular uptake—results in a significant spike in blood glucose concentration.
The Timeline of Hyperglycemia
The increase in blood sugar following a cortisone injection begins relatively quickly as the medication is absorbed from the injection site. The hyperglycemic effect typically starts within 6 to 12 hours after the injection, reaching peak elevation around one to three days after the procedure.
For individuals who do not have diabetes, the blood sugar increase is usually transient and modest, often returning to normal baseline levels within 24 to 48 hours. The elevation may be less than 40 milligrams per deciliter (mg/dL) above their usual range.
The impact is far more pronounced and sustained for people with pre-existing diabetes. In these patients, peak blood glucose levels can be substantially higher, sometimes reaching the 300 mg/dL range. The duration of the spike is also longer, persisting for three to seven days, and occasionally up to ten days, depending on the specific corticosteroid and dosage. Patients with less controlled diabetes are likely to experience a more extreme and prolonged period of elevated sugar.
Monitoring and Management Strategies
Managing the temporary rise in blood sugar requires different strategies depending on whether the patient has a history of diabetes. For individuals with known diabetes, it is important to communicate with a primary care provider or endocrinologist before receiving the shot. This consultation allows for the creation of a temporary management plan, which usually involves increasing the frequency of blood glucose monitoring to four times a day, especially after meals.
The most common strategy for people on insulin is a temporary adjustment in dosage, which can sometimes involve an increase of 150 to 200 percent of the usual dose for the days when the cortisone effect peaks. People using oral diabetes medications may also require temporary medication changes or the initiation of insulin therapy to safely manage the spike. These adjustments should only be made under the guidance of a healthcare professional.
For the general public who do not have a diabetes diagnosis, the primary focus is on awareness and symptom recognition. The most common symptoms of severe hyperglycemia include feeling unusually thirsty and needing to urinate more frequently than normal. If these symptoms occur, it is advisable to contact a doctor for guidance on temporary monitoring. A doctor should be contacted promptly if blood sugar readings are consistently over 200 mg/dL on two separate occasions or exceed 300 mg/dL at any time.
Supportive measures for everyone include prioritizing healthier food choices, such as reducing carbohydrate intake, and staying well-hydrated during the week following the injection. For most people, the blood sugar will normalize once the corticosteroid is fully metabolized and removed from the body.