A cortisone shot is an injection used to reduce localized swelling and pain caused by inflammation in a specific area of the body. The injection typically contains a corticosteroid, a manufactured drug resembling the natural hormone cortisol, mixed with a local anesthetic. This combination targets various inflammatory conditions, such as arthritis, bursitis, and tendinitis. Common injection sites include large joints like the knee, hip, and shoulder, as well as smaller areas like the hands and feet. The goal is to provide temporary pain relief, enabling a patient to participate more effectively in physical therapy or rehabilitation.
The Immediate Timeline Procedure and Flare
The actual process of receiving a cortisone injection is quick, often taking only a few minutes. A healthcare provider cleans the injection site and may use a local numbing agent before inserting the needle. In some cases, the provider uses ultrasound or an X-ray technique called fluoroscopy to guide the needle precisely into the target area.
Following the injection, some people experience a temporary worsening of pain and swelling known as a “cortisone flare.” This reaction is caused by the crystallization of the corticosteroid medication within the tissue. The flare is brief, typically peaking within the first 24 hours and resolving completely within 48 hours.
During this initial period, patients should protect the injected area and avoid strenuous activity. While returning to normal daily activities is usually permissible, high-impact exercise or heavy lifting should be avoided for at least 24 to 48 hours. Using ice or a cold pack on the injection site can help manage any temporary discomfort or swelling.
Onset of Therapeutic Action
The immediate pain relief felt by some patients is due to the local anesthetic mixed with the corticosteroid, which provides a fast but short-lived numbing effect. This anesthetic typically wears off within a few hours, often coinciding with the start of the temporary cortisone flare. The corticosteroid component, responsible for the long-term therapeutic effect, does not start working right away as it needs time to interact with inflammatory cells.
For most people, the true anti-inflammatory action begins to take effect within two to seven days after the injection. Significant improvement in pain and swelling is usually noticed once the corticosteroid has reduced the localized inflammation. The exact timing depends on the severity of the inflammation being treated and how long the condition has been present.
Factors such as the specific area treated influence the speed of onset. Injections into a small, contained space like a bursa or a joint may provide relief sooner than those targeting a larger area of diffuse inflammation. The type of corticosteroid used also plays a role, as different formulations have varying rates of release. If no benefit is felt within two or three weeks, the injection may not have been effective.
Duration of Relief and Limits on Frequency
Once the corticosteroid takes hold, the duration of sustained pain relief varies widely. Typically, the positive effects of a cortisone shot last anywhere from several weeks to several months. A common range for relief is between six weeks and six months, often depending on the underlying diagnosis.
The longevity of the pain relief is influenced by multiple factors, including the specific condition, the joint involved, and the patient’s lifestyle. For example, a shot for acute tendinitis may last long enough for the injury to heal fully. In contrast, a shot for chronic osteoarthritis provides temporary relief that diminishes over time. Patient activity level and adherence to physical therapy also impact how long the effect lasts.
Limits on Frequency
Due to concerns about potential side effects, there are limits on how frequently a person can receive a cortisone shot in the same location. Medical professionals commonly recommend limiting injections to no more than three or four per year in a single joint. This guideline mitigates the risk of complications such as tendon weakening, cartilage damage, or bone tissue changes.
A minimum waiting period of at least three months (12 weeks) is typically advised between injections into the same area. This allows the body time to recover and reduces cumulative exposure to the medication. If relief wears off quickly or the condition requires frequent repeat injections, the healthcare provider may suggest reassessing the diagnosis or exploring alternative treatments.