A cortisone shot is an injection used to relieve pain and reduce inflammation in specific areas of the body, such as joints, tendons, or bursae. The injection typically contains a corticosteroid medication, which decreases the inflammatory response, and a local anesthetic, which provides immediate, temporary pain relief. The experience of pain is highly variable, depending on the injection site, the technique used by the practitioner, and the individual’s pain sensitivity.
The Acute Pain During the Procedure
The immediate sensation experienced during the procedure is typically not intense, but a patient will feel two distinct sources of acute pain. The first source is the initial penetration of the skin by the needle, often described as a brief, sharp sting. This sensation is highly influenced by the size of the needle used and whether a numbing spray or cream was applied to the skin beforehand.
The second source of acute discomfort occurs as the medication is injected into the target area, often felt as a pressure or deep ache. This feeling is caused by the physical volume of the fluid being delivered into a confined space, like a joint capsule or a tight tendon sheath. Shots into deeper, tighter joints like the hip may cause more pressure-related pain than those into a superficial bursa.
To counteract this immediate pain, the cortisone shot is usually mixed with a local anesthetic, such as lidocaine or bupivacaine. This anesthetic provides rapid numbness, often within moments, which can alleviate the pressure sensation as the rest of the medication is delivered. However, the feeling of pressure as the fluid enters the tissue remains a common sensation.
The Common Phenomenon of Post-Injection Soreness
After the immediate numbing effect of the local anesthetic wears off, typically a few hours later, a distinct form of discomfort known as a “cortisone flare” may occur. This is a temporary inflammatory reaction that can cause a short-term increase in pain, swelling, and irritation at the injection site. The flare is a recognized side effect that affects approximately one in five people who receive the shot.
This phenomenon is caused by the corticosteroid medication itself, which is formulated as a suspension of slow-release crystals. As these crystals settle into the tissue before they dissolve and begin their long-term anti-inflammatory action, they can temporarily irritate the surrounding joint or soft tissue. The typical onset for this soreness is between 4 and 48 hours after the procedure, and it is distinct from the mechanical pain of the injection itself.
This post-injection soreness is self-limiting and generally short-lived, with symptoms usually subsiding within one to three days. Management involves resting the affected area for 24 to 48 hours and applying ice to the injection site. Over-the-counter pain relievers, such as acetaminophen, can also be used to manage the discomfort. The steroid typically begins to take effect within two to five days.
Practical Steps to Minimize Discomfort
Medical professionals employ several techniques to minimize a patient’s discomfort during the injection process. One common strategy is the use of numbing agents, which may include a topical cold spray applied to the skin before the needle insertion. Alternatively, the practitioner may inject a small amount of local anesthetic just under the skin to numb the needle pathway before the main injection.
Precision is a major factor in reducing pain, and many injections are now performed using real-time imaging guidance. Utilizing ultrasound or fluoroscopy allows the provider to visualize the needle’s path and ensure accurate placement of the medication. This guided approach significantly reduces the potential for misplaced injections, which can increase pain.
Following the procedure, patients are advised to protect the treated area for a day or two to allow the medication to settle. This often means limiting weight-bearing activity for knee injections or avoiding heavy lifting for shoulder injections. This temporary restriction helps prevent undue stress on the treated tissues, which could aggravate localized soreness and contribute to a post-injection flare.