Why do I feel so good after a cortisone shot? The Science of Relief

October 7, 2025 •

5 min read

Epidural steroid injections have a success rate of 50% to 84% for relieving chronic pain. If you've had one, you might wonder, 'Why do I feel so good after a cortisone shot?' The answer lies in its powerful anti-inflammatory action and potential temporary systemic effects.

Quick Summary

A cortisone shot provides relief by mimicking the body's natural stress-response hormone, cortisol, to powerfully suppress inflammation at a specific site, which in turn reduces pain. This targeted approach allows for healing and improved function.

Key Points

Primary Action: Cortisone shots work by delivering a powerful synthetic steroid to a specific area to drastically reduce inflammation, which is the main source of pain.
The 'Good Feeling': The relief you feel is a combination of dramatic pain reduction and, for some, a mild, temporary systemic effect of the steroid that can cause increased energy or temporary mood changes.
Not a Painkiller: Cortisone itself does not block pain signals; the pain relief is an indirect result of its potent anti-inflammatory action.
Cortisone Flare: About 1 in 5 patients may experience a temporary worsening of pain for 24-48 hours after the injection, known as a 'cortisone flare,' before the medication takes full effect.
Temporary Solution: The effects of a cortisone shot typically last from a few weeks to several months but do not cure the underlying condition.
Frequency Limits: Due to risks like cartilage damage, injections into the same joint are typically limited to 3-4 times per year.
Systemic Side Effects: Though localized, some medication can enter the bloodstream, potentially causing insomnia, facial flushing, or temporary increases in blood sugar.

Understanding Cortisone and How It Works

Cortisone is a synthetic corticosteroid, a drug that mimics cortisol, a hormone naturally produced by your adrenal glands. Cortisol plays a vital role in your body's stress response, which includes suppressing inflammation. When you receive a cortisone shot, a powerful dose of this anti-inflammatory medication is delivered directly to a problem area, such as a painful joint, tendon, or bursa.

The primary mechanism of a cortisone shot is to decrease the local inflammatory response. Inflammation is your body's natural reaction to injury or disease, but it also causes pain, swelling, and irritation. Cortisone works by shutting down the cells that produce inflammatory substances and collagen in the treated area. This suppression of inflammation calms irritated nerves, leading to significant pain reduction. It's important to note that cortisone is not a painkiller itself; the pain relief is an indirect result of reduced inflammation. Most injections also contain a local anesthetic to provide immediate, short-term pain relief while the steroid takes a few days to become effective.

The 'Feel Good' Sensation: Pain Relief and Systemic Effects

The profound sense of well-being after a cortisone shot stems from two main factors: powerful pain relief and potential temporary systemic effects. The primary reason is the dramatic reduction in pain. By quelling inflammation, cortisone allows for improved joint function and a return to activities that were previously too painful, providing a significant quality-of-life boost.

However, a small amount of the corticosteroid can be absorbed into the bloodstream, leading to systemic effects throughout the body. While usually minor, these can include temporary psychological effects. For some individuals, this might manifest as feeling more energized or experiencing temporary mood changes. These mood changes are a known, though not universal, effect of corticosteroid therapy and tend to occur shortly after treatment begins. The dosage is a significant factor for these psychological symptoms, with higher doses increasing the likelihood of such reactions. Other common systemic side effects include temporary insomnia and facial flushing.

The Timeline of Relief and the 'Cortisone Flare'

After a cortisone shot, the included anesthetic provides immediate pain relief that wears off within a few hours. The corticosteroid itself typically begins to work within a few days, with most people feeling its effects within a week. The full benefits can provide pain relief for several weeks to several months, depending on the individual and the condition being treated.

However, some people experience a temporary 'cortisone flare.' This is a brief period, usually lasting 24 to 48 hours after the injection, where the pain and inflammation in the area actually worsen. This reaction is thought to be caused by the body's initial response to the steroid crystals being deposited in the joint. While uncomfortable, it is temporary and can be managed with ice and over-the-counter anti-inflammatory medications. It does not indicate that the treatment will be ineffective; in fact, significant pain relief often follows the flare.

Conditions Treated and The Injection Procedure

Cortisone shots are used to treat a wide range of musculoskeletal conditions where inflammation is a key component of pain.

Arthritis: Including osteoarthritis, rheumatoid arthritis, psoriatic arthritis, and gout.
Tendonitis: Inflammation of a tendon, such as in the shoulder (rotator cuff), elbow (tennis elbow), or wrist.
Bursitis: Inflammation of the bursae, the fluid-filled sacs that cushion joints, commonly affecting the hip, knee, or shoulder.
Back Pain: Often used for conditions like sciatica or herniated discs via epidural injections.
Other Conditions: Including plantar fasciitis, carpal tunnel syndrome, and frozen shoulder.

The procedure is straightforward and performed in a doctor's office. The area is cleaned, and a local anesthetic may be applied to the skin. Using a needle, the doctor injects the cortisone and anesthetic mixture into the targeted joint, bursa, or tendon sheath. For deeper or more complex joints, the doctor might use ultrasound or X-ray (fluoroscopy) to guide the needle to the precise location.

Comparison of Joint Injection Therapies

Cortisone is not the only injectable treatment for joint pain. Hyaluronic Acid (HA) and Platelet-Rich Plasma (PRP) are other common options, particularly for knee osteoarthritis.


Feature	Cortisone Shot	Hyaluronic Acid (HA)	Platelet-Rich Plasma (PRP)
Mechanism	Potent anti-inflammatory; suppresses immune response locally.	Acts as a lubricant and shock absorber within the joint.	Uses growth factors from your own blood to stimulate tissue healing and repair.
Onset of Relief	Fast-acting for flare-ups, usually within days.	Slower onset, may take several weeks for full effect.	Gradual improvement over weeks to months.
Duration of Relief	Short-term; typically lasts a few weeks to several months.	Moderate duration, can last for a few months.	Longest lasting; can provide relief for 6-12 months or more.
Primary Use	Rapid relief from acute pain and inflammation flare-ups.	Mild to moderate osteoarthritis pain; lubrication.	Repair and regeneration; long-term pain management.
Risks	Cartilage damage with repeated use, infection, tendon rupture, cortisone flare.	Pain at injection site, swelling.	Low risk of reaction since it uses the patient's own blood; infection risk is minimal.

Recent evidence suggests that for knee osteoarthritis, PRP provides more significant and longer-lasting improvements in pain and function compared to both Cortisone and HA. Cortisone remains the best option for rapid, short-term relief of severe flare-ups.

Conclusion: A Powerful but Temporary Solution

That remarkable feeling of well-being after a cortisone shot is primarily due to its potent ability to stamp out inflammation, thereby relieving pain and restoring function. For some, a mild, temporary sense of increased energy can also contribute. While these injections offer powerful and rapid relief for many painful conditions, they are not a cure. The effects are temporary, and there are limits and potential risks, especially with repeated use, such as cartilage and tendon damage. It is generally recommended to have no more than three or four injections in the same area per year. Ultimately, a cortisone shot is a valuable tool for managing acute pain, allowing a window for physical therapy and other rehabilitative treatments to address the underlying cause of the problem.

For more information from an authoritative source, you can visit the Mayo Clinic's page on Cortisone Shots.

Frequently Asked Questions

While the local anesthetic in the shot provides immediate but temporary relief, the cortisone itself typically takes a few days to a week to start working and reduce inflammation.

A cortisone flare is a temporary reaction that can occur within 24-48 hours of the injection, causing increased pain and swelling at the site. It usually resolves on its own and is often followed by pain relief.

The pain relief from a cortisone shot can last anywhere from a few weeks to six months or longer, depending on the condition being treated and the individual's response.

Yes, it is generally recommended to rest the injected area for a day or two and avoid strenuous activity. You should also avoid using a bathtub or hot tub for two days to prevent infection, though showering is fine.

To avoid potential side effects like cartilage damage or tendon weakening, doctors typically limit injections to no more than three or four times per year in the same joint or area.

Common, minor side effects include a temporary flare of pain, facial flushing, insomnia, and a temporary increase in blood sugar levels, especially for people with diabetes.

Yes, though less common with localized injections than oral steroids, some people may experience temporary mood changes, including feeling more energized, or experiencing anxiety or irritability as a systemic side effect.