A cortisone shot, also known as a corticosteroid injection, delivers a potent anti-inflammatory medication directly into a localized area of the body. The purpose of this injection is to reduce inflammation and alleviate associated pain in specific musculoskeletal structures, such as a joint, tendon, or bursa. Corticosteroids are synthetic drugs that mimic cortisol, a hormone that helps suppress the body’s immune response. This targeted approach provides relief for conditions like arthritis, bursitis, and tendinitis, allowing patients to improve mobility and participate in physical therapy. The shot manages the symptoms of pain and swelling but does not cure the underlying condition.
The Timeline of Relief
The pain relief offered by a cortisone shot is not immediate and follows a predictable pattern. Many injections combine the corticosteroid with a local anesthetic, which offers immediate but short-lived numbing relief that wears off within a few hours. Once the anesthetic fades, patients may experience a temporary increase in pain and swelling known as a “cortisone flare,” which can last up to 48 hours.
The main therapeutic effect of the corticosteroid usually begins within 24 to 72 hours following the injection. This is when the medication starts actively reducing inflammation in the targeted tissue. Peak effectiveness is often felt within about one week. The duration of relief is highly variable, ranging from several weeks to as long as six months.
On average, a successful cortisone shot provides pain relief lasting between 6 to 12 weeks, though relief up to six months is not uncommon. The relief is temporary because the corticosteroid does not fix the root cause of the pain. Pain and inflammation return as the drug is absorbed and metabolized by the body.
Variables That Affect Longevity
The exact length of pain relief is influenced by several biological and mechanical factors specific to the patient and the injury.
Location and Formulation
The location of the injection is a variable, as injections into larger joints like the knee or shoulder may last longer than those in smaller joints or soft tissues. The type of corticosteroid formulation used also affects duration, as some are designed for a slower, more sustained release.
Condition Severity
The underlying medical condition and its severity play a substantial role in how long the benefit lasts. Patients with acute inflammation or less advanced conditions may experience a longer period of relief. Conversely, individuals with chronic, advanced conditions like severe osteoarthritis may find the effects wear off sooner due to ongoing joint tissue degradation.
Patient Factors
Patient activity level immediately following the injection impacts longevity, as excessive strain or high-impact activities can reduce the duration of the pain-free period. Systemic health factors, such as having diabetes, can alter the body’s response to the cortisone, sometimes leading to a shorter duration of effectiveness. Combining the injection with physical therapy and rehabilitation is recommended to maximize the shot’s utility and extend the relief.
Safety and Frequency of Re-treatment
Since cortisone shots offer temporary relief, patients often inquire about receiving repeated injections when pain returns. Healthcare providers adhere to a guideline limiting injections to the same area to no more than three or four times per year. This restriction manages the risk of complications associated with frequent corticosteroid exposure.
A minimum waiting period of at least three months (twelve weeks) is recommended between injections into the same joint. Frequent use of corticosteroids in the same location can lead to complications:
- Weakening or rupture of tendons.
- Atrophy of the skin.
- Damage to the joint cartilage.
- Bone damage or tissue death.
If the pain relief becomes progressively shorter with each subsequent shot, it signals that the underlying problem is advancing and the treatment is losing effectiveness. In these situations, physicians shift the focus to exploring more definitive, long-term treatment solutions. These alternatives include surgical options or intensive rehabilitation programs designed to address the root cause of the pain.