Leg joint pain most often comes from wear-and-tear arthritis, overuse injuries like tendinitis or bursitis, or an old injury that never fully healed. The specific cause depends heavily on which joint hurts, where exactly in that joint you feel pain, and whether the pain came on suddenly or built up over time. About 54% of adults over 75 have diagnosed arthritis, but joint pain affects younger people too, with nearly 4% of adults aged 18 to 34 already carrying a diagnosis.
Wear-and-Tear vs. Inflammatory Pain
The single most useful distinction is whether your joint pain is mechanical (from physical wear on the joint) or inflammatory (from your immune system attacking joint tissue). Mechanical pain, like osteoarthritis, tends to feel worse after activity and better after rest. You might notice stiffness after sitting for a while, but it loosens up within a few minutes of moving around. Osteoarthritis develops slowly and typically appears after age 45, though previous injuries can trigger it earlier.
Inflammatory joint pain works differently. The hallmark is morning stiffness lasting an hour or more after you wake up. The stiffness and aching often improve once you start moving, but the pattern is less predictable than mechanical pain. Rheumatoid arthritis, gout, and lupus all fall into this category. If multiple joints are swollen and stiff at the same time, especially on both sides of your body, that points toward an inflammatory cause rather than simple wear and tear.
Where Your Knee Hurts Matters
The knee is the most common leg joint to cause trouble, and the location of your pain narrows the possibilities significantly. Pain on the inner side of the knee often involves the medial collateral ligament or the medial meniscus, the crescent-shaped cartilage pad that cushions the inner knee. These injuries typically come from twisting movements or direct impact. Pain on the outer side points toward the lateral meniscus, the lateral collateral ligament, or a tight iliotibial band (the tissue running along the outside of your thigh).
Pain behind the knee has a wider range of causes, from a posterior meniscus tear to nerve compression. In some cases, it can signal a blood clot in the vein behind the knee. If you notice swelling in your calf along with pain behind the knee, especially after a period of immobility like a long flight, that warrants prompt medical attention.
If your knee catches, locks, or gives way, that usually means something structural is disrupted inside the joint. Meniscus tears and ligament injuries like ACL tears are the most common culprits. A joint that clicks without pain is generally harmless, but a joint that locks in place or buckles under weight is a different story.
Hip Pain Isn’t Always in the Hip
Hip joint problems typically cause pain in the groin or front of the thigh, not on the side of the hip where most people point when they say “my hip hurts.” That side-of-the-hip pain is more commonly from greater trochanteric pain syndrome, which involves inflammation or damage to the tendons and bursa on the outer hip. It’s especially common in middle-aged women and people who are overweight. The telltale sign: it hurts to sleep on the affected side.
True hip joint problems, like osteoarthritis, labral tears, or impingement, produce pain deep in the groin that worsens with walking, sitting for long periods, or rotating the leg. Younger, active people are more prone to labral tears and impingement. Older adults more commonly develop osteoarthritis or, in rarer cases, loss of blood supply to the femoral head from factors like long-term steroid use, heavy alcohol consumption, or certain blood disorders.
Pain in the back of the hip and buttock is often not a hip joint problem at all. Deep buttock pain that worsens with sitting, especially in a car, and shoots down the leg is more likely related to nerve compression in the spine or deep gluteal syndrome. This overlaps with sciatica, where a herniated disc or bone spur in the lower back pinches the sciatic nerve, sending pain along its path through the buttock, back of the thigh, and into the calf. Sciatica can feel exactly like a hip or knee problem even though the source is in your spine.
Ankle Pain That Won’t Go Away
Chronic ankle pain is frequently the result of an old sprain that didn’t heal completely. When you sprain an ankle, you damage the ligaments, but you also disrupt the sensory feedback system that tells your brain where your ankle is in space. Even after the ligament heals, you can be left with a sense of instability, weakness, or pain that flares unpredictably. This is why ankle sprains have such a high re-injury rate.
Other sources of persistent ankle pain include tendinitis from overuse, arthritis (particularly post-traumatic arthritis after a fracture or severe sprain), and ankle impingement, where scar tissue or bone spurs at the front of the ankle get pinched during movement. Gout also commonly strikes the ankle, causing sudden, intense pain with redness and swelling.
Pain That Starts Somewhere Else
Not all leg joint pain originates in the joint itself. Sciatica is the most common example. A pinched nerve in the lower back can produce pain anywhere along the nerve pathway, from the buttock through the back of the thigh and calf. People frequently describe this as hip pain or knee pain because that’s where they feel it most, even though the actual problem is a herniated disc or bone spur compressing a nerve root in the lumbar spine.
Sacroiliac joint dysfunction in the pelvis can mimic hip pain. Abdominal or pelvic conditions, including issues related to the bowel, bladder, or menstrual cycle, can refer pain to the hip region as well. If your joint looks normal, isn’t swollen, and moves through its full range without pain when examined, the source may be upstream.
Managing the Pain at Home
For a new injury or a sudden flare-up, the standard approach starts with rest, ice, compression, and elevation during the first 24 to 72 hours. Apply ice for 10 to 20 minutes at a time, three or more times per day. An elastic bandage can help control swelling and provide support. Keep the joint elevated when possible, including overnight.
After the initial swelling subsides, usually within a couple of days, gentle movement becomes the priority. Moving the joint increases blood flow and promotes healing. A small amount of controlled stress on injured ligaments actually supports stronger tissue growth. As pain allows, gradually increase your activity level, protecting the joint from impact but not immobilizing it. Over-the-counter pain relievers like ibuprofen or acetaminophen can help with short-term pain management during this transition.
For chronic joint pain from osteoarthritis or overuse, the evidence consistently favors staying active over resting. Low-impact activities like swimming, cycling, or walking maintain joint function and strengthen the muscles that support the joint. Physical therapy is particularly effective for persistent pain, as a therapist can identify muscle weaknesses or movement patterns contributing to the problem and build a targeted plan around them.
Signs That Need Prompt Attention
Most joint pain improves with basic home care and time, but certain symptoms indicate something more serious. A joint that looks deformed, can’t bear weight, or swells suddenly after an injury needs same-day evaluation. Severe pain that comes on without an obvious cause also falls into this category.
Outside of acute injuries, make an appointment if you notice joint swelling, redness, warmth around the joint, or fever alongside the pain. These signs suggest infection or an inflammatory condition that won’t resolve on its own. A hot, red, swollen joint with fever can be a medical emergency if it’s caused by a joint infection, which can permanently damage cartilage within days if untreated.