An arthritis flare-up in the knee can be managed at home with a combination of ice, over-the-counter anti-inflammatory medication, gentle movement, and temporary activity modification. Most flares involve a sudden increase in pain, swelling, and stiffness that makes it harder to walk, bend, or bear weight on the affected leg. The key is reducing inflammation quickly while keeping the joint from stiffening up completely.
What’s Happening Inside Your Knee
During a flare, the cartilage cushioning the ends of your bones has worn down enough that the joint becomes irritated and inflamed. This isn’t just a cartilage problem. The soft tissue lining the joint swells, the connective bands holding everything together weaken, and the bone itself can change shape over time. That swelling is what drives most of the pain and limited range of motion you feel during a flare.
Common triggers include overuse (a long walk, yard work, or an unusually active day), a change in weather, weight gain, or a minor tweak to the joint. Extra body weight is particularly hard on knees because it adds direct mechanical stress and because fat tissue produces proteins that promote inflammation in and around joints. Sometimes flares seem to come out of nowhere, with no obvious trigger at all.
How Long a Flare Typically Lasts
Flares can persist for weeks or months if nothing changes in how you’re managing the condition. With active treatment, though, you can shorten that window significantly. Mild flares that respond to home care often improve within a few days to a couple of weeks. More severe flares, particularly in rheumatoid arthritis or other inflammatory types, may require prescription medication to bring under control.
Ice, Heat, and When to Use Each
Both ice and heat help with arthritis pain, but they do different things. Ice reduces swelling and numbs sharp pain, making it the better first choice when your knee is visibly swollen, warm to the touch, or throbbing. Apply an ice pack wrapped in a thin towel for 20 minutes at a time, with breaks in between.
Heat loosens stiffness and improves blood flow, so it works well in the morning when your knee feels locked up or before gentle movement. A warm towel, heating pad, or warm bath can all work. The Cleveland Clinic suggests a practical daily pattern: heat in the morning to warm up the joint, ice later in the day to cool down inflammation. If your knee is actively inflamed and swollen, lean toward ice first. Once the swelling settles, heat becomes more useful.
Over-the-Counter Pain Relief
Ibuprofen is one of the most accessible options for a knee flare because it reduces both pain and inflammation. The Arthritis Foundation recommends 200 to 400 mg every four to six hours as needed, up to a maximum of 1,200 mg per day for over-the-counter use. Take it with food to protect your stomach. Naproxen is another option that lasts longer per dose, so you take it less frequently.
Topical anti-inflammatory gels applied directly to the knee can also help, especially if oral medications bother your stomach. These deliver the active ingredient locally with less systemic absorption. For flares that don’t respond to over-the-counter options within a few days, your doctor may recommend a short course of a stronger prescription anti-inflammatory or a corticosteroid.
Gentle Movement That Won’t Make It Worse
Complete rest feels instinctive during a flare, but too much inactivity makes stiffness worse and weakens the muscles that support your knee. The goal is gentle, controlled movement that maintains your range of motion without loading the joint heavily.
Start with five to ten minutes of low-impact warmup, like slow walking or riding a stationary bike with minimal resistance. From there, three stretches recommended by the American Academy of Orthopaedic Surgeons target the muscles around the knee:
- Heel cord stretch: Stand facing a wall with your affected leg straight behind you, heel flat on the floor. Lean your hips toward the wall until you feel a stretch in your calf. Hold for 30 seconds.
- Standing quadriceps stretch: Hold a chair for balance, bend your knee, and gently pull your heel toward your buttock with one hand. Hold for 30 to 60 seconds. This targets the front of your thigh, which directly affects how your kneecap tracks.
- Lying hamstring stretch: Lie on your back with both knees bent. Lift the affected leg, clasp your hands behind your thigh, straighten the leg, and gently pull it toward you until you feel a stretch behind the knee. Hold for 30 to 60 seconds. A looped towel around your thigh makes this easier if you can’t reach comfortably.
If any movement increases your pain rather than just producing mild discomfort, stop. The point is to keep the joint from seizing up, not to push through a workout.
Knee Braces and Support
A knee brace can make walking and standing more manageable during a flare. For arthritis specifically, unloader braces are the type most commonly recommended. They work by redistributing your body weight away from the damaged part of the knee to other areas of the leg, which directly reduces the pressure causing pain. These are different from simple compression sleeves, which provide mild support and warmth but don’t redirect force.
If you don’t already have an unloader brace, a basic compression sleeve can still offer some comfort and proprioceptive feedback (that sense of the joint feeling more stable). For longer-term flare management, ask your doctor about being fitted for an unloader brace, since they need to match the specific compartment of your knee that’s affected.
When a Flare Needs Medical Attention
Most flares are painful but manageable. Some symptoms, however, signal something more serious. A knee that becomes rapidly swollen, hot to the touch, and red, especially with fever or an inability to move the joint at all, could indicate a joint infection (septic arthritis). This is a medical emergency that requires fluid to be drawn from the joint for testing. Septic arthritis can cause permanent joint damage if not treated quickly with antibiotics.
You should also seek care if your flare doesn’t improve after one to two weeks of consistent home treatment, if the pain is severe enough that you can’t bear weight, or if you notice the knee locking or giving way.
Steroid Injections for Severe Flares
If home measures aren’t enough, a corticosteroid injection directly into the knee joint is one of the most effective options for breaking a stubborn flare. The injection typically includes both a steroid to reduce inflammation and a numbing agent for immediate pain relief. Expect some increased pain and swelling for up to two days after the shot as the joint reacts. After that initial period, the anti-inflammatory effect kicks in and pain relief can last up to several months.
Steroid injections aren’t something you’d get frequently. Repeated injections can weaken cartilage and surrounding tissues over time, so most doctors limit them to a few per year in the same joint. They’re best used as a bridge to get a severe flare under control while you work on longer-term strategies like strengthening exercises, weight management, or adjusting your daily medication.