A cortisone shot is a powerful anti-inflammatory treatment delivered directly into a specific area, such as a joint, bursa, or tendon sheath, to reduce swelling and pain. This targeted approach uses a synthetic version of the hormone cortisol, often combined with a local anesthetic, to interrupt the body’s inflammatory cycle at the source. Following this procedure, healthcare providers consistently advise patients to avoid submerging the injection site in water, including pools and hot tubs, for a short period. This is a standard precaution to protect the patient from potential complications.
The Primary Concern: Protecting the Injection Site from Contamination
The primary reason for avoiding submersion is the significant risk of introducing bacteria into the body through the microscopic puncture created by the needle. Although the procedure is performed under sterile conditions, the injection temporarily breaches the skin, the body’s largest protective barrier. This creates a tiny, unsealed channel that extends from the skin surface down to the targeted tissue or joint space.
Bodies of water, even chlorinated swimming pools and hot tubs, are reservoirs for various microorganisms. These environments harbor bacteria such as Pseudomonas aeruginosa and staphylococcus. When the injection site is submerged, water pressure and the presence of these pathogens increase the chance of them migrating through the open needle tract.
Joints are particularly vulnerable because they are isolated spaces with limited blood flow, meaning the immune response to an infection there can be slow. If bacteria reach the joint space, it can lead to septic arthritis, which requires immediate and aggressive medical treatment. Showering is permitted because the exposure to running water is brief and the site is not submerged, minimizing the risk of pathogen entry.
Essential Timing: When Is It Safe to Submerge the Area?
The restriction on submerging the injection site is temporary, lasting only until the skin’s protective barrier is fully restored. Medical guidance typically recommends avoiding baths, hot tubs, and swimming pools for 24 to 48 hours after the procedure. This window allows enough time for the small puncture wound left by the needle to clot and seal over completely.
The precise length of this restriction can vary based on the location of the injection and the size of the needle used. Injections into deeper joints, like the hip, may warrant a slightly longer period of caution compared to more superficial injections.
Always follow the specific timing instructions provided by the physician who administered the shot, as they will tailor the advice to your procedure and overall health status. Once the tract is sealed, the external risk of waterborne infection drops back to the normal level.
Complete Post-Shot Guidelines and Warning Signs
Patients should adhere to other post-injection care guidelines beyond avoiding water submersion. It is advised to protect the injected area and avoid strenuous activities or heavy lifting involving that joint for at least 24 to 48 hours following the procedure. This period of limited activity helps keep the injected corticosteroid concentrated in the target area, maximizing its anti-inflammatory effect.
For immediate pain management, patients may be instructed to use ice packs on the injection site for 15 to 20 minutes at a time, several times a day. This addresses the temporary increase in discomfort, sometimes called a “steroid flare,” that some people experience as the local anesthetic wears off and before the corticosteroid takes full effect.
A significant part of post-shot care involves monitoring the area for signs of a potential complication or infection. While rare, an infection is a serious concern that requires immediate medical attention. Warning signs include:
- Increasing redness and warmth spreading out from the injection site.
- Persistent or worsening pain that lasts more than 48 hours.
- Excessive swelling or the presence of pus.
- Fever or chills.
If any of these symptoms develop, contact your healthcare provider immediately.