Corticosteroid injections, often called steroid or cortisone shots, are a common medical treatment used to reduce inflammation and pain in localized areas like joints, tendons, or bursae. These injections deliver powerful anti-inflammatory medication directly to the affected site, providing rapid relief for conditions such as arthritis or tendinitis. While patients often ask if these shots cause sleepiness or fatigue, the immediate pharmacological effect is generally the opposite of drowsiness. The active drug mimics a powerful natural stress hormone, causing stimulation and wakefulness rather than a sedating effect.
The Actual Effect on Sleep and Energy
The drugs used in a steroid shot are synthetic glucocorticoids, which are designed to imitate the body’s natural stress hormone, cortisol. Cortisol is a key component of the hypothalamic-pituitary-adrenal (HPA) axis, the system responsible for regulating the stress and wake-sleep cycles. By introducing a potent dose of this cortisol-mimicking substance, the injection essentially triggers a temporary state of heightened alertness.
This stimulation can manifest as a feeling of being “hyper,” similar to the sensation experienced after consuming too much caffeine. Because the steroid acts on the same pathways as cortisol, a common acute side effect is insomnia or difficulty falling asleep and staying asleep. This period of wakefulness and increased energy can last anywhere from one to three days following the procedure. The steroid’s presence acts as a strong signal to the brain, overriding the natural signals that promote rest.
The body’s HPA axis responds to the synthetic steroid by temporarily slowing its own production of natural cortisol. The presence of the external hormone suppresses the release of adrenocorticotropic hormone (ACTH) from the pituitary gland, leading to a transient decrease in the adrenal glands’ output. While the initial effect of the synthetic steroid is stimulating, this suppression can lead to a period where the body is adjusting its hormonal balance, which can contribute to later fatigue.
Why Patients Might Feel Tired After a Steroid Shot
Despite the stimulating nature of the medication, some patients report feeling tired or lethargic shortly after receiving the shot, which is attributed to several secondary factors. The most common cause is the direct result of insomnia experienced in the first few days post-injection. The sleep disturbances caused by the steroid’s stimulating effect result in accumulated sleep debt, leading to daytime fatigue.
Another significant contributor is the relief from chronic pain and inflammation, which can be exhausting in itself. Chronic pain forces the body into a persistent state of high alert, consuming significant mental and physical resources. When the steroid shot finally breaks this cycle of pain and tension, the body can crash into a state of post-relief exhaustion as it finally allows itself to relax.
Metabolic changes can also play a role in temporary fatigue. Corticosteroids can temporarily cause blood glucose levels to rise, particularly in individuals with diabetes. Fluctuations in blood sugar can lead to feelings of sluggishness and general malaise. This combination of poor sleep, pain relief, and transient metabolic changes explains why tiredness often occurs despite the medication being stimulating.
Managing Common Acute Side Effects
Since the most prevalent sleep-related side effect is insomnia, focusing on good sleep hygiene in the days following the injection is beneficial. Patients should avoid stimulants like caffeine and alcohol, especially in the afternoon and evening, to help regulate their sleep cycle. Creating a cool, dark, and quiet environment and maintaining a consistent bedtime routine helps counteract the steroid’s stimulating properties.
Beyond the sleep effects, patients may experience other common acute side effects that require simple management. A temporary increase in pain and swelling at the injection site, known as a “steroid flare,” can occur within the first 24 to 48 hours. Applying an ice pack to the area for 15 minutes at a time helps reduce this localized discomfort and inflammation.
Some individuals also experience temporary facial flushing or a feeling of warmth, which typically fades within a few days. For patients with diabetes, it is important to monitor blood sugar levels more frequently for up to a week after the injection, as the steroid can cause a temporary spike in glucose. Discussing any significant or persistent side effects with a healthcare provider ensures the best recovery and management plan.