What Are The Disadvantages And Side Effects Of Cortisone Injections?

Cortisone injections can calm a painful joint or inflamed tendon quickly, but they are not a free pass. The main disadvantages are a temporary rise in blood sugar, skin and fat changes at the injection site, a small risk of infection, short-term pain flare, and the fact that relief often fades within weeks to months. Repeated injections into the same area can also weaken tendon or cartilage over time.

Most side effects are local and short-lived. Serious complications are uncommon but real. The decision to get one comes down to weighing fast, targeted relief against those risks — and knowing when the shot is buying time rather than fixing a problem.

What Are The Disadvantages And Side Effects Of Cortisone Injections?

Cortisone is a synthetic version of cortisol, a hormone your body makes naturally. It is a strong anti-inflammatory, and injecting it directly into a joint, bursa, or tendon delivers a concentrated dose right where the inflammation sits.

That targeted delivery is the appeal. It is also why the side effects tend to cluster around the injection site and the days right after the shot.

The disadvantages fall into a few groups:

• Local reactions — pain flare, skin thinning, lightening of skin color, and fat loss under the skin.
• Systemic effects — mainly a temporary rise in blood sugar, and less often flushing or mood changes.
• Infection risk — rare, but the most serious concern.
• Structural effects from repeat use — potential weakening of tendons or cartilage with frequent injections.
• Temporary relief — the shot often quiets symptoms without addressing the underlying cause.

None of these are reasons to avoid a cortisone injection outright. They are reasons to go in with clear expectations.

What Happens at the Injection Site?

Most cortisone side effects show up right where the needle went in. They are usually mild and temporary, but a few can last months or longer.

A pain flare is common. Some people feel more soreness in the first day or two after the shot than they did before it. This is sometimes called a post-injection flare. It usually settles within a couple of days and is not a sign the injection failed.

Skin changes are among the more persistent local effects. Cortisone can thin the skin over the injection site. It can also cause a patch of lighter skin, especially in people with darker skin tones. In some cases this color change does not fully fade.

Fat atrophy — a small dent or dimple where fat under the skin shrinks — can appear after an injection. It is more common with superficial injections and can be permanent.

Infection is rare but serious. A joint infection (septic arthritis) is a medical emergency. Watch for spreading redness, heat, swelling that worsens after the first day or two, fever, or chills. Those symptoms need prompt medical attention, not a wait-and-see approach.

Bleeding or bruising at the site is possible, particularly for people on blood thinners. Tell your clinician about any anticoagulant medication before the procedure.

Can Cortisone Injections Raise Blood Sugar?

Yes — this is one of the best-documented systemic effects. A cortisone injection can raise blood glucose for a period of time afterward, and the effect is more pronounced in people who already have diabetes.

The rise is usually temporary. How high it goes and how long it lasts depends on the dose, the injection site, and the person. Larger joints and higher doses tend to produce a bigger effect than a small injection into a tendon sheath.

If you have diabetes, this is worth planning for rather than discovering. Some clinicians advise checking blood sugar more often for several days after the shot. The exact monitoring window and any medication adjustment should come from your own care team — there is no single universal protocol that fits everyone.

People without diabetes can also see a temporary bump in blood sugar, but it is typically smaller and less clinically significant.

How Long Does Relief Last — and What Happens With Repeat Injections?

Cortisone injections are often effective for weeks to a few months. They are not usually a permanent fix. The inflammation quiets, but the underlying problem — arthritis, a tendon injury, a mechanical issue — is still there.

That short window matters. A shot that buys pain-free weeks can be genuinely useful if it lets you do physical therapy or rebuild strength. It is less useful if it simply masks pain while you keep loading a damaged structure.

Repeat injections raise separate concerns. Corticosteroids can weaken tendon tissue when given repeatedly into the same tendon. This is why many clinicians limit how often they will inject a given tendon and space injections out.

For joints, the picture is more debated. Some research suggests repeated intra-articular steroid injections may be associated with cartilage changes over time, but the evidence is not settled and results vary. What is clearer is that frequent injections into the same joint are generally not recommended as an ongoing strategy, and clinical practice tends to favor spacing them out and using them sparingly.

There is no single number of injections that is safe for everyone. Ask your clinician what their limit is and why.

Are There Systemic Side Effects Beyond Blood Sugar?

Most cortisone injections stay largely local, but some steroid does reach the rest of the body. Systemic effects are usually mild and short-lived with typical doses.

Some people notice facial flushing in the day or two after an injection. Others report temporary mood changes, trouble sleeping, or a brief burst of energy. These tend to resolve on their own.

More significant systemic effects — like suppression of the body’s own cortisol production — are a concern mainly with frequent, high-dose, or long-term steroid use, not with occasional single injections. The risk rises with cumulative exposure.

Rare but reported effects include tendon rupture, particularly with injections directly into certain tendons such as the Achilles. This is uncommon, and it is one reason some clinicians are cautious about injecting directly into a tendon versus the tissue around it.

Who Should Be Cautious About Getting One?

Cortisone injections are not right for everyone, and some conditions call for extra caution rather than an automatic yes.

People with an active infection near the injection site, or a systemic infection, generally should not get a cortisone injection. Injecting steroids into an infected area can worsen it.

People with poorly controlled diabetes face a bigger challenge managing blood sugar after the shot. That does not automatically rule it out, but it changes the planning.

People on blood thinners need to discuss bleeding risk with their clinician beforehand. So do people with a known allergy to any component of the injection.

There is also a practical caution that gets less attention: a cortisone injection can temporarily mask pain. Feeling better does not mean the tissue has healed. Returning to full activity too fast — heavy lifting, running, or repetitive strain — can aggravate the very problem the shot was meant to calm. Some clinicians advise relative rest for a short period after the injection, though specific guidance varies.

Pregnancy and breastfeeding deserve a direct note. Corticosteroid use in pregnancy and lactation is a decision that belongs with an obstetric clinician. Established guidance on injected corticosteroids in these populations is limited, and no universal recommendation covers all situations. This is not a decision to make on your own.

What Are the Alternatives?

Cortisone is one tool among several, and for many conditions it is not the first-line choice for long-term management.

Physical therapy addresses strength, movement, and loading patterns — the factors that often drive the underlying problem. It takes longer than a shot but targets the cause rather than the symptom.

Nonsteroidal anti-inflammatory drugs (NSAIDs) can reduce pain and inflammation, though they carry their own gastrointestinal and cardiovascular risks with regular use.

Activity modification and rest let irritated tissue settle. Ice or heat can help with comfort, though evidence for either is modest.

Other injection types exist — for example, hyaluronic acid injections for knee osteoarthritis — but their effectiveness compared with corticosteroids varies by condition and patient, and the evidence is mixed. They are not a universal substitute.

The right choice depends on what is actually wrong. A cortisone injection can be a reasonable bridge. It is rarely a complete plan on its own.